Computer Monitor Repair
Updated November 11, 2003
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| QUESTION NO. P101503-4: Acana Peripherals 17s monitor FCC IIB-UA1. I need the value of burned R472, R473, R492, R493 and R495. |
| In the TVM schematic, I read R472 as 1K; R473 as 20K; R492 as 1M; R493 as 51K; and R495 as 10K. But these likely died from a bad flyback, T404, which would need replacing. |
| QUESTION NO. P101503-8: Dell 1028L monitor. What is the value of the ph-33d? |
| Without the component's chassis location number, the service literature cannot be referenced, but this may be a Philips fast-recovery type rectifier, BYD-33D, rated 200 Volts, 1 Amp. Possible substitutes for that one, are FR103, NTE552, or NTE574. |
| QUESTION NO. P100603-2: Viewsonic E70, burnt R457 resistor, next FBT. Need the value of resistor. Caused by s/c c445 connected to collector of FB transistor Q407. |
| There are many different Viewsonic E70 models, so without the 'VCDTS' model number, one cannot be sure which one is your model. However, the E70-3 version does have its R457 connected to the collector of Q407 via a capacitor (the other end of R457 goes to the base of PNP Q426, in that E70 version), and in that chassis, R457 is 1.5K Ohms, 1/2 Watt. |
| QUESTION NO. P100103-7: HP D2817A monitor. I need the value of R612 (surface mount resistor at the bottom of the PCB). |
| R612 is 270K Ohms; its size is larger than most SMD, could be a 2010 size (1/2 Watt). |
| QUESTION NO. P082703-4: LG Studioworks 99T monitor, Q520 is fried. Part reads K2379, seems to be Sanyos mosfet 2SK2379. Part is impossible to get in Germany, are there any equivalent replacements? |
| Although Sanyo's 2SK2379 is a logic-level gate Mosfet, in the LG 99T circuit, Q520's gate is driven by a 12 Volt source, so a standard-gate Mosfet like Fairchild's IRFS650B or SSS45N20B (or SSP45N20B with an insulator) might substitute for 2SK2379 in this location. |
| QUESTION NO. P092503-10: evokd1730 (Vs-7) monitor. I need reference Q 411. |
| Q411 is BU2525AF. |
| QUESTION NO. P082503-2: DA-456 CRT Monitor. I need the values of D406, R475 and R471. |
| D406=1N4148, R475=10Kohm 1/4W, R471=30Kohm 1/4W |
| QUESTION NO. P090403-6: Viewsonic G810 VCDTS 23852-6M monitor, horizontal scan is missing on the right side. There is distortion of the scanning lines before they peter out. |
| If there is a bad blanking pulse at pin 17 of IC601, on the CRT board, one possible way to restore the blanking pulse, is to change the value of R460 (100K) to 15K Ohms, to increase the base drive for Q4412. |
| QUESTION NO. P081803-10: LKOM L705 monitor is dead, power supply working, the led is on but no EHT. Collector has 50 volts of HOT transistor but no signal on base of the transistor. The chip is TDA9115 but no output at vertical and horizontal output sections. |
| .50V on the collector of the transistor is ok but if the base does not have it to turn it on the transistor will not conduct or turn on and that 50V will not go to ground or its proper place. As for TDA9115 no output [check for the correct voltage, ground, input to the unit]. Maybe something is loading the output of the TDA9115 down. If disconnect the output and check it again. |
| QUESTION NO. P090303-5: Acer 7276e monitor FCC JVP7276E. I need the value of C326 by the HOT and value and location of FR101. I was told to also check F701, F702, F703, F704, J013, R326, R328, R241, R329, C327, C304, D308, L304, ZD210, IC201, Q301, Q302, and Q316. |
| The Acer 7276e schematic shows C326 as 270 pF/500V. FR101 (2A) is on the CRT board, on the +85V line, located between pin 4 of the 5-pin plug M103, and C170. |
| QUESTION NO. P090303-3: KDS monitor FCC EVOKD-1910T, what is the part number for the FBT? |
| In a KDS AV-195T with this FCC number, KDS used FBT type Y265432B. Also, H.R. Diemen claims that their FBT type HR46206 is a replacement for Y265432B. |
| QUESTION NO. P082803-5: Nec MULTISYNC 95F monitor is missing R31A, I need the value. |
| Assuming this NEC is chassis N9902, R31A appears to be 0.33 Ohm, 1 Watt, fusible. |
| QUESTION NO. P082703-7: Acer 7178ie monitor FCC JVP7178ie. Arcing or sparking at the neck board between ground to either F1 or F2. The flyback has 4 wires output, one is High voltage, G2, the other two wires just guessing are either F1 and F2. Is the flyback (# TLF 063-11-39) defective? |
| Yes, arcing at the focus pins is a common fault from a defective 7178ie flyback. The Acer number for this flyback is 19.70033.011. The TLF063-11-39 is not the actual flyback number, that number is just for the focus pack. |
| QUESTION NO. P082503-4: Compaq V90 monitor FCC BR8SM-994. I need the value of burned R866. |
| R866 is 2.2 ohms, flameproof. |
| QUESTION NO. P082503-5: Samsung45bn monitor has a white screen but no picture. Checked the HOT, the two 220 diodes are ok. All main diodes are fine. Did in circuit testing of all small transistors, they show no shorts. Checked 53 volts 70 volt and 12 volt they are fine. The hot heatsink heats abnormally, nothing else heats up or blows. Switching on function is normal, I can hear is degauss and then back, the led also stays green. |
| I replaced 1rf 630 near the buttons and it fixed the problem. |
| QUESTION NO. P082203-4: Proview 986M monitor FCC IJE986. What are the values of Q663 and Q664? The board is version 200-100-PR98E rev: F3+. |
| Q663 and Q664 are shown as being either KSC5042F, or 2SC4686A, in the schematic. Possible alternatives are 2SC4630, or a 2SC3675 with insulator hardware added. B&D Enterprises (ww.bdent.com) is one source for these transistors. |
| QUESTION NO. P082203-3: LG Flatron 775FT monitor. I need the equivalent for FJAF6812 horizontal transistor. |
| Possible substitutes for FJAF6812 include 2SC4890, 2SC5411, BU4525AX, and NTE2365 with an insulator. |
| QUESTION NO. P082103-4: Sony/Sun gdm 20e20 monitor has a flickering picture, not horizontally centered and unstable vertically in a jumping back and forth fashion. All voltages are ok and no damage to pcbs can be found. |
| These sort of faults can be caused by a defective IC007 = CXA1908S, Sony p/n# 8-752-076-34, on the "D" board. Often, replacing this IC then requires DAS software re-alignment of the screen geometry parameters. |
| QUESTION NO. P081803-9: Samsung Sync Master 753S & 750s monitor. I need the part number of the FBT. |
| For Samsung chassis DP17L, two FBT's are listed, FEA831 (BH26-00035A), or FQB17A001 (BH26-00026A). FEA831 and FQB17A001 should be similar, or the same, for they cross to the same HR Diemen equivalent, HR46203. For Samsung chassis AQ17LS, the FBT is listed as LCE-CF1781, Samsung part code BH26-00109A. |
| QUESTION NO. P71103-4: NEC V520(B) monitor without FCC #. The power is ok and LED indicate green but no display. No HV and relay does not click. Checked HOT it's ok. Checked all resistors, diodes and transistors at power supply and deflection area and looks all ok. |
| Try resoldering tube connections, especially G2. |
| QUESTION NO. P72503-1: Optiquest V95 Model vcdts2183 monitor FCC GSS1900 the horizontal sync is way out, the picture is only 4 inches wide. I think LM1292N IC is bad but can't locate one. I used to purchase IC's from LJ but his site is no longer there. |
| LJ Enterprises' new web address www.ljecc.com/ |
| QUESTION NO. P70803-3: Sony CPD-E220 monitor power supply and HV are ok but low G2 and switches on with signal then shuts down after 30 seconds steady orange flashing led. |
| These units are lemons. Sony will replace between certain serial numbers because they cannot supply eeproms & microprocessors. Do not try to fit blank eeprom or it will blow in a big way. |
| QUESTION NO. P73103-6: Sampo km718dt monitor chassis c718. I need values of R509 and C503. |
| In my Sampo KM-718 manual, R509 is 22 Ohms, 2 Watts, and C503 is 0.047 uF, 400V. |
| QUESTION NO. P72903-9: KDS monitor FCC EVOKD-1910T. I need substitute part for transistor A1281 at location Q818. |
| A possible substitute could be Fairchild's FPN660, but its pinout is EBC, instead of ECB, so its leads would need to be inserted correspondingly. Mouser Electronics (www.mouser.com) is listing FPN660. |
| QUESTION NO. P72103-10: NEC multisync FE700+ monitor, all digital alignment controls work except width and pincushion. If problem is processor please mention source for same. |
| In many digital monitor it happens that there width and pincushion control doesn't work other all controller functioning ok. This problem is due to the Transistor which control the Horizontal Size. mostly it is located on the center of the circuit board. Look for the Transistor B649A and replace it. Some time there are more then one so if there are then check them all and replace the defective one. |
| QUESTION NO. P72103-9: KDS Multiscan color monitor FCC EVOKD-1910. is dead, components are burnt. I need the value and part numbers of Q424, Q818, IC 403, R424, R466, R468, R462. |
| I have EVOKD-1910T here, I think it is quite similar so I'll try to help a bit. Q424 is 400V N-Channel MOSFET IRFS730, IC403 is SMPS Controller KA3842B (the same as IC404 you have there), R424 is 3600 ohm, R468 is 1 ohm. Have you check yr flyback? I could not locate Q818 (Q810?). My R466 and R462 are burnt too, waiting others to help. |
| R466=1k ohms 1/4w R462=10 ohms1/4w. |
| QUESTION NO. P72903-8: HP M70 D5259A monitor, chassis D5259-60050, I need value R451 |
| HP has installed several different chassis in model D5259A, but if yours is a Tatung C7B chassis, the schematic for the Tatung C7B shows R451 as 1.5K ohms. |
| QUESTION NO. P72503-7: Viewsonic P810 monitor is dead. I replaced a shorted horiz. output transistor. It is still dead but now there is a ticking noise from the power supply. |
| Viewsonic has made several different versions of P810, with different FCC and VCDTS numbers, so specific tips cannot be given. However, in general, when HOT's short in these, the B+ regulator FET (usually a P-channel FET) is also bad. Sometimes also, the damper diode, and/or diodes on the SMPS secondary 200 Volt rail, are bad, or fuses or fusible resistors in the B+ supply line are open. Also check the base drive circuit components for that shorted HOT. In some models, bad FBT's are common. |
| QUESTION NO. P72803-3: Viewsonic G790 model VCDTS21385-1M monitor. Initial fault was arcing on the FBT. I replaced it (FEA661). No arcing but no operation either. Q303 (2SC5331) and Q103 ( IRF740) were shorted. Q303 is the HOT ;Q103 is a regulator in the HV circuit. Replaced both and tested again. Q303 shorted again but not Q103. The HVOPT (Q105, C5124) never blows. Q601 (the B+ regulator in the HOT circuit) was tested OK but replaced anyway. Also tested damper diode D304, D317, and R334. What is causing Q303 to short? |
| I have located the culprit. It was D123 (shorted) in the G1 circuit output of the FBT. It looks like the load on the HVOP was causing the B+ on the HOT to wildly fluctuate and take out the HOT. |
| QUESTION NO. P72503-3: Apple M6496 Studio Display monitor no FCC or model number, made by LG Electronics. There is no B-plus to the horizontal output transistor, Q707. I have carefully checked the board with a magnifying glass. |
| Check that B+ voltage passes through P-FET regulator Q404. Also check C411, ultrafast D405, and damper D714. If there are no pulses on the gate of Q404, check R439, zener D404 (18V), and ascertain that horizontal drive is being provided to Q404's gate from IC701. |
| QUESTION NO. P72503-5: HP D2837 monitor, when the power is turned on, the unit draws 50 watts constant, the raster pulsates about 4 times per second. The pulsating starts in the center and expands outward about 1/2 inch both horizontally and vertically. The B plus voltage holds steady at 88 volts. The High Voltage "vibrates" at 27.5 |
| Assuming this HP model is FCC#A3LCKB722, I would check C517 (3.3 uF, bipolar); the schematic lists it as 50V, but sometimes the manufacturer has skimped on this one's voltage rating. If C517 is OK, then check the flyback. |
| QUESTION NO. P72303-10: AOC monitor spectrum 4v has power green led but has no display. |
| Check diode near power supply, damper diode (her 303,stpr 303). |
| QUESTION NO. P72403-3: Dell p991 19 Sony monitor, I am measuring 30 KV for high voltage and unless I lower brightness and contrast down to 30% of full the monitor goes into shutdown. How can I lower HiV to 26-27 KV? When I pull crt socket off the tube all is OK, so I'm guessing its excessive beam current. |
| According to the manual, HV is adjusted to 27KV by RV901 (on D board, under a cover and RTV silicone). Also, check components in the HV regulatory circuit (R924, R925, RV901, IC901, and FBT T901), and the HV and ABL protection circuits (R917, R918, R920, R921, R923, R932, R933, R191, R1004, R1006, C920, D911, D912, D915, D917, IC901, T901), in case any are off-value or faulty. Note, Defective FBT's (Sony p/n# 1-453-317-11) are one cause of 30KV HV in this model. |
| QUESTION NO. P72403-9: Samtron SC 726GXL monitor FCC A3LCMH737. I need value of C506 |
| According to the SC-726GXL manual, C506 is a metallized polypropylene film capacitor, 0.33 UF, 400 Volts, 5% tolerance. |
| QUESTION NO. P72303-3: Proview px561 monitor. I need the reference of the transistor Q630 . |
| Q630 is IRF634, or an equivalent type. IRF740A can also substitute. If Q630 is bad, also replace C635, and carefully check D632 for reverse leakiness. |
| QUESTION NO. P72203-5: Compaq MV520 monitor displays bad horizontal width problems. Can adjust vertical ok using setup adjustment controls but not horizontal width or position. I have changed IC U401 and U2. |
| Compaq MV520 has several chassis versions, with different CO-xxxxx model codes, but if your version has a dual diode at D801, check it for bad solder, and for reverse leakiness in the diodes. If D801 has problems, also check FET's Q802 and Q805, in case D801 has damaged them. |
| QUESTION NO. P70803-9: Philips 107E20/00Z monitor, I need type of power mosfet in power supply section part number 7101. It is some ST microelectronics type but cannot read because burnt badly. |
| The original part is SSP7N60A. A substitute part is IRFB9N60A. The Philips part number is 9322 135 00687. |
| QUESTION NO. P72103-1: Dell GDM-5001PT monitor does not respond to the controls for vertical center and vertical size, also has pincushion on both sides. How do I reset ic007 in the D board, CXA-2043Q like Samsung TV's? |
| This Dell is a Sony, not a Samsung, chassis. The symptoms sound more like a defective IC007, than one that needs realigning via Sony DAS software. If you replace IC007, beware of lifting the fine PCB traces. Sony distributors have CXA2043Q, as Sony part number 8-752-078-46, or MCM Electronics may have the generic part available. |
| QUESTION NO. P71703-4: Compaq 150 Model 445A monitor, Chassis CM0200, FCC A3KM050. Phillips Manufactured, but no help there. Of course Compaq recommends replacement. R3423, R3424, R3426 burned. Need values. Vertical IC shorted after powering it up with the cable connecting the mask to the CRT Board unhooked. (Looking for loose solder connections). Anything else I should be looking at? Vert IC replaced, of course. |
| In my Philips manual for CM0200, R3423 is 220 ohm, 0.33 Watt; and both R3424 and R3426 are 4.7 ohm, 0.5 Watt. |
| QUESTION NO. P71503-1: Viewsonic GS815 monitor, I need the part number of the vertical IC. |
| The vertical IC is TDA8172; also check nearby electrolytic capacitors for possible damage from incorrect supply voltages. |
| QUESTION NO. P71003-7: LG Studioworks 74m monitor, FCC BEJCM710. Initial problem was no go with ticking sound. Checked H.O.T which was ok. Replaced Flyback Transformer, and monitor now operates BUT only when the video cable is not plugged into the rear of the monitor. As soon as I plug the cable in the monitor goes into standby mode, and B+ goes high. |
| Check the B+ coil and capacitors, coil is to left of fbt near p/supply inspect closely for burning and test value, check the fet also. Every now and then one of these will do more damage when the fbt goes, some only the fbt. |
| QUESTION NO. P71003-8: Samsung 550S (DP15LS) monitor, I cannot adjust the colors, no screen pots(red, blue, green), no driver pots, no DAS connectors. |
| Color adjustments on the DP15LS model are done with Samsung's Softjig software, and the Samsung Softjig interface assembly (interface board Ver. 2.0, and signal cable). |
| QUESTION NO. P71003-4: HP D2825 monitor FCC 7154E. Display was split into two parts horizontally and about 3inch diagonal bar was in the center of the screen. I checked H stage. I changed H.O.T (BU2520AF), now Q317 N CHANNAL F.E.T (K2161) is blowing. I replaced it with IRF 740 but, its also over heats & seams to be burned. Also need value of zener diode D316. Another problem is when connect the Vga cable, the front panel controls does not work. When Vga cable is disconnected the front panel controls (Bright, Contrast, Size, etc) work. |
| First change ceramic cap C335 (220pF/2KV), by the flyback. If R214 (15K) is bad, IC201 (TDA4858) is probably also bad. Since Q317 repeatedly burns, also check if coil L304 has burnt or shorted windings, or has lost inductance (L304 should retain at least 0.7 mH in inductance), and check zener D316 (24V), ultrafast diode D317, and C326. |
| QUESTION NO. P71003-3: Compaq mv520 monitor has 240 volts (Australia) in to board power supply but nothing else to the rest of the board, front led flashes dimly. |
| Replace Q505 (IRF630) FET mounted on FBT cage. Dry joints on FBT and C513 (100uF200V) swollen. But any heavy drain on the supply could cause this. |
| QUESTION NO. P70903-4: Dell P1110 monitor, G2 dies out after 1 to 2 hours, spraying coolant on Q406 brings back the picture. Q406 is surface mounted with no visible markings, what is the generic part #? |
| In the Sony Manual, Q406 is either a Matsushita 2SB709A (in the schematic), or a Toshiba 2SA1162 (in the parts list); these two PNP transistors have similar specs. The parts list shows Q406 as 2SA1162-G (G = gain bracket 200-400), and Sony p/n# 8-729-216-22. |
| QUESTION NO. P70903-5: Digital CMC-1511BW/SM monitor Chassis CMC-1509B was dead. Replaced damaged transistor (FET) 2sj449 (part #Q133) and main H-Out transistor 2sc4924 (part #q500). Now monitor is on but is not showing any picture signal coming from the VGA of the computer. I checked the vga with another monitor which worked fine. In the standby mode some tick tick sound coming from the relays RL501 and RL503 near the H-Out transistor and in full working mode the noise coming from the flyback or near around the flyback. |
| With Q133 and Q500 bad, I would also check R150 (10 ohm); C539; ultrafast rectifier D132; and the rectifier for the 200V secondary supply off the SMPS transformer. |
| QUESTION NO. P70803-10: Tatung C7BZR monitor. I need a substitute for a dmv-32 or dmv-56. Its a damper/modulation diode pack in a transistor case. |
| Possible substitutes for ST Micro's diodes DMV32B and DMV56 include Sanken's types FMP-2FUR, FMQ-2FUR, FMT-2FUR; also, Fairchild's type FFPF60B150DS. |
| DMV32B diode is available in UK from http://www.dalbani.co.uk/index.php |
| QUESTION NO. P70703-4: IBM 6556-03N monitor Sony chassis SCC-LO7G-A raster is tearing top 1/3 of screen, improves as it warms up. Worse in high resolution modes. |
| Check C575; also check C573, since the problem is worse in certain modes. |
| QUESTION NO. P70703-2: AOC 7klr monitor. Need value of r626, burnt beyond recognition. |
| Value of R626 is 820E 1w. After replacing screen shows thin lines and foldover on top. Changed TDA 4866 and electrolytics around this IC. Fixed the problem. |
| QUESTION NO. P62303-10: Kimodo K7 Sceptre monitor is dead after not being used for three months. No known damage nor surges. PLED blinks short on, long off. |
| Next time include size, proper make, model, year, FCC ID, UL and CSA. Your unit is a 17" Komodo (Sceptre) computer monitor model P773, part number:K73P, year: March 10,1999, FCC GKRM773,UL:1K97. Your unit like 70% of all of those chassis have a defective T802=FEA632 (Sampo)=flyback which takes out the HOT,Q503=2SC5387 which could be subbed for ST2408HI,BUH1015HI,BU2508AF or 2SC3886./ |
| QUESTION NO. P60503-1: Compaq mv520 monitor. What is the correct line output transistor fitted to this chassis? |
| Line output transistor is BU4508AX |
| QUESTION NO. P52903-7: AppleVision 850 Monitor was originally intermittent, when display would disappear. This seemed to be a heat-related problem, as monitor would power up normally after letting it stand for some time. Disassembled monitor, and resoldered some suspect joints. This fixed the intermittent problem. Monitor then lost display, with no obvious signs of overheated components. Now when powered up, and video signal asserted from computer, power LED blinks ORANGE at about 2Hz. Are there any points where critical DC voltages can be checked? |
| Check vertical IC and caps. If I remember correctly pins 6 & 7 or pins 5 & 7 will short. |
| QUESTION NO. P61903-10: Apple Multiple Scan M2494 FCC AK8M2494. About 10 ~13 seconds after turning on the unit, picture gets so bright (with retrace lines) causing the unit to shut down. All main voltages test ok; G2 voltage is about 1kv at the source, but seems to have an automatic G2 regulation circuit at the CRT module. |
| Check tube socket connections for dry joints. These units lift smd components on video board near the heat sink component side. Also check microprocessor output. |
| QUESTION NO. P61703-2: Dell D1626HT monitor (Sony chassis SCC-L04K-A) with no red color. After check and replace de IC403 (FA4111) without result, I think the problem can be caused by malfunction of IC402 (M52722P). I haven't any datasheet of M52722P and I can't find in Mitsubishi Semiconductor site. |
| In the schematic, the Red input to IC402 is to pin 17, and is about 2.8V. Red drive (pin 18) is about 3.9V, Red hold (pin 35) is about 4.4V, and Red Output (pin 37) is about 2.7V. Vcc for red (12VDC) is IC402, pins 16 and 36; red ground pins are pins 24 and 29. Red output goes to transistor Q101 (PNP, base is about 2.8V, emitter is about 3.5V), then continues on to input at IC403. If another IC is needed, IC402 (M52722P) is Sony part number 8-759-468-63. |
| QUESTION NO. P61703-3: Nokia 447x258 monitor. Need part number for T27 FET. |
| T27 is IRF9622, a P-channel Mosfet; an IRF9620 could substitute. |
| QUESTION NO. P61703-5: Acer 7156e monitor, JVP7156E totally dead. Checked all resistors, transistors, diodes and caps in primary side. Replaced ic uc3842 but did not help. When switched ON, main capacitor still holds current. Double checked all component in primary and secondary. |
| Unfortunately in this monitor a charged cap does not mean much. The main drive is not the IC you changed but IC701 via an opto coupler so if there is a short say on the flyback IC701 will lock down and C612 will be fully charged. I then suggest check the usual output transistor etc and ring the flyback if you can. |
| QUESTION NO. P60903-2: Hyundai S560 monitor has narrow screen. I need the value of burned Q312, I can make out K D2. |
| Q312 is D2061 |
| QUESTION NO. P60603-3: Samtron 750S or 753S monitor with Eprom IC 24C04, first MENU never use to come when I replaced 24C04 (ST make China) first instant it worked correct, but after switch on again the width becomes less, I tried with next IC, again the same thing, I tried with 24C08 of other make same thing again. |
| After replacing the eeprom you need to do an alignment with Samsung's Softjig software and interface. After doing the alignment, save the data to the eeprom. |
| QUESTION NO. P61203-9: Samsung Syncmaster 15GLI monitor. I need values of R609, R610, R616 & zener diode D610. |
| R609=0.18ohm 1W, R610=1K ohm 1/6W, R616=15K ohm 1/2W, D610 = 16V zener( UZ-16BM). |
| QUESTION NO. P61203-8: Compaq V75 model 623T monitor. I replaced FBT (FEA662), Q831 (BU2520?), R866 (2.2 Ohm 1/4W). I want to be sure about Q831, is it supposed to be a BU2520DF (with damper diode) or BU2520AF (without damper diode)? |
| The version of BU2520 used for Q831 is BU2520DF (contains a damper). |
| QUESTION NO. P61203-10: HP D5259A monitor Chassis C-711 has a horizontal line across the screen. Resoldered cracked solder joints at I602 (vertical IC), still horizontal line. R618 is fried, what is its? |
| R618 is 1 ohm. Also check if the vertical chip is damaged. |
| QUESTION NO. P61203-2: Philips 107e monitor, power supply contains smps ic which is TEA1504. I need a replacement from other manufacturers. |
| That is a specialized chip made by Philips so forget about other makers. |
| QUESTION NO. P60503-8: NEC P1250 monitor with vertical field collapse. i.e. a horizontal line is visible in the center of the screen. I have replaced the IC104 but the problem remains. |
| No vertical deflection has a specific troubleshooting procedure. 1st. Check vertical yoke winding connections on PCB and measure. resistance of winding with yoke unhooked from PCB (expect 8.2-11 ohms). 2nd. Locate B+ pin of Vertical Output IC and check for DC voltage typical 25-27VDC. 3rd. Locate vertical sync input pin of OUTPUT IC and check for sync in lack of sync means VERTICAL drive missing from further back in circuit typical cause is 2.2 uf cap @50 vdc series coupling. 4th. Look for a 100uf cap at cathode of B+in diode negative will go to pin labeled PUMP or RAMP if this cap has low ESR no vertical defl will occur and output DC reference voltage will be 50-70% of documented value. 5th. Some vertical circuits use a series defl cap in the range of 1000-3300 UF. if this cap is open no deflection will occur. Other variations use less than 1 ohm resistors from NEGATIVE of this cap to ground. Poor solder (heat stress) oropen resistors take cp out of return line and thus NO DEFLECTION. |
| QUESTION NO. P61003-10: Proline 7G1r monitor FCC ARSCM7850 was DOA, Q811 was faulty and R8090 was burnt, I guessed at the value of R8090 to be approx 190 ohms, I replaced these components, after switch on the resistor starts to burn again, the whole area around these components and the KA3842 IC, was stained, almost like sea air corrosion, but only in a confined area. |
| In an AOC-brand model with the same FCC number, R8090 was 22 ohms, 2 Watts. Besides checking Q811, other components that might be checked are Q812, Q823, C827, C828, C837, D806, D807, and check for any shorted windings in T804. The KA3842 IC may also have been damaged, and try to clean the stain off the PCB. |
| QUESTION NO. P60903-9: EMC Multisystems SA-770 monitor FCC IJE765 has a shorted Q630 (IRF634A). What other parts should I check or replace along with this mosfet so it doesn't short again? |
| Check the flyback transformer and output transistor, one or both are faulty. |
| Along with Q630, the ultrafast rectifier D632, and electrolytic C635, should also be replaced, as they are usually marginal or defective, as well (may not test totally bad). It has been suggested to reduce the value of C635, from 22 uF/250V, to 10 uF/250V. |
| QUESTION NO. P60603-5: TVM AS6S monitor. I need the value of R473. |
| R473 is 20K ohms. When R473 burns, this is likely caused by a defective flyback transformer. |
| QUESTION NO. P60603-7: Nec pn7701 monitor with open R304. Can't read the color code. |
| R304 is 3.3 Ohms. |
| QUESTION NO. P60503-5: Daytek DT-1501BA1 monitor FCC DTSCMC1501BA has horizontal line/squashed picture center of screen. Resoldered five bad solder joints on vertical deflection circuit (TDA1675A) still have horizontal line. |
| Replace that IC. It is a common failure in other monitors. Also the cause is probably bad caps (4) connected to that IC. Then replace the b+ resistor (low value) connected to pin 14 which also has one of the caps on it. |
| QUESTION NO. P60203-3: KDS VIEW K770 monitor, the horizontal output transistor (BU 2520-DF), C499 (220P 2kv) & R457 were burned. I need the value of R457. |
| This KDS model is a Jean chassis. R457 is 680 ohms, 1/2 Watt, and you probably meant disk capacitor C449, not C499. Also check Q426 and Q429 for potential damage. |
| QUESTION NO. P50503-1: I need the vertical ic number for a Samsung Syncmaster 950p monitor. |
| If this Samsung Syncmaster 950p is a PG19LS, then IC301 is TDA8172. |
| Samsung shows multiple chassis for this model. AQ19 IC301 as a KA2142, PG19 IC301 as a KA2142. |
| QUESTION NO. P52903-4: AOC 7Glr monitor. I need the value of R913 and R914. |
| R913 4.7K 5% 1/4W, R914 47 ohm 5% 1/4W. |
| QUESTION NO. P52903-1: HP D2818A monitor. I need the number of Video IC IC 102 Missing (12Pin IC). |
| IC102 is LM2427. |
| QUESTION NO. P52703-3: HP d2825 monitor cannot adjust horizontal size and has pincushion problem. Replaced TDA4858, checked many components. Other functions o.k. |
| Check Q302, Q303, R302, C316, L303, and D308. The semiconductors might be leaky, but not totally shorted. |
| QUESTION NO. P51903-5: LG studio works 775N monitor, is too dim. I checked power supply voltages they seem ok. There is no burnt resistor or blown capacitor. |
| More than likely your CRT has low emission. Had a lot of these fail at the end of the 3 year warranty. LG ran out of replacement CRT's in Canada. |
| QUESTION NO. P52203-2: Goldstar (LG) 1465DLs monitor FCC BEJCH480; Chassis: CA-32. R726 burned (need value for replacement), also C723 (need value and specifications) seems burned too, both related to the FB. If both would be replaced, will they burn again? |
| R726 is 10K ohms, and C723 is 1 uF/63V. These were probably burned by a defective flyback, so the flyback would also need replacing, or they are liable to burn again. |
| QUESTION NO. P42803-2: Acana Peripherals 17s monitor. I need the value of burned R495 and the cause. |
| If this Acana 17S is FCC# IIB-UA1, the schematic for that chassis shows R495 as 10K ohms. Since this R495 connects to the flyback transformer, a defective flyback might have burned R495. |
| QUESTION NO. P51603-1: HP d2827a monitor, the hot has blown and I replaced it with a Bu2520df. The ht is ok. When switched on the relay goes on and off with a tweaking sound. All voltages are correct with the hot disconnected. Is the bu2520df tre right transistor? |
| If this HP is a Daewoo 518X chassis, Daewoo's schematic shows BU2520DX, which is the same as BU2520AF electrically, except a different case style, so a BU2520AF should work in that chassis. |
| QUESTION NO. P51603-9: Apple iMac 233 Mhz monitor. When powered on, it goes through a procedure of bringing up the computer section of the iMac and then the monitor. When it gets as far as firing up the monitor board, there is a repeated snapping sound for between 1 and 5 seconds (I can see a small blue flash somewhere near the Motorola control chip), and then powers off and does not come back up unless left for an hour or so. I can't see any burnt components on the board, but the top of the Motorola IC (LGM871-010/AYJ) appears to have heat damage (it's not a continuous black color on top like most ICs). I have found only one supplier for the IC and it's $49 + shipping to the UK, so I don't want to replace it unless I know it is broken. |
| The most common fault is shutdown due to an arcing flyback transformer, a common fault in the 233 MHz iMac. LG is one source for flyback 6174Z-1003G, or in some regions, an H.R. Diemen equivalent may be easier to obtain. |
| QUESTION NO. P51503-7: Sony cpdg500 monitor, brightness too high with all controls set at lowest possible. Image is stable and in focus, all syncs and geometry ok. Suspect defective ic in brightness circuit, possible voltage too high. No adjustments internally, all micro-controlled. |
| Assuming that this is a circuitry fault, rather than a DAS software issue, the problem might be, that the CRT cathode voltages are too low, or the G2 voltage is too high. On the CRT board ('A' board), check if the cathode voltages (CRT pins 7,8,9) are in the 80 to 100 Volt range. If these voltages are too low, it may indicate a bad IC403 (FA4301). The G2 voltage (CRT pin 10) should be roughly 522 Volts at the CRT. If G2 is much higher, check the G2 circuit, involving transistor pair Q406 & Q410, run by IC405 (pin 7), under control from IC404 (pin 14). Otherwise, try a DAS alignment. |
| QUESTION NO. P41703-1: Proline C409A monitor FCC IQX97C1455 is dead. R122, R121, R130, Q101 and Q704 are all burned beyond recognition. I need the values. All other components are tested and seems OK. |
| R121 is 220 ohms, R122 is 120 ohms, R130 is 10 Kohms, Q101 is 2SK2545, and Q704 is 2SC5339. R121 and R122 form a voltage divider across R120, which is 0.47 ohms, and is the source return resistor for the MOSFET switch, Q101. The junction of R121 and R122 goes to R110, 1000 ohms, which then feeds the current sense input of U101, which is a KA3882 PWM controller. It seems unlikely that R121 and R122 could be burned unless R120 is open, and even then I would expect to see R110 burned unless there's a short on the board. |
| QUESTION NO. P51203-7: Gateway EV700A monitor FCC BEJCB775B Voltage cycles. 5 Volts okay but all others cycle. I replaced FBT and IC923, IC925. |
| Also check IC304, the 8 Volt regulator IC on the CRT board, and its solder connections. |
| QUESTION NO. P50903-5: Apple IMAC 266 Model M4984 monitor. Is there an alternative flyback to 6174Z1017D (LG)? Local LG list only 1017A or E. The A is not a cross but the E may be. Perhaps the E is an upgrade? |
| In iMac M4984, flyback# 6174Z1017D can be replaced by LG FBT# 6174Z-1003G. |
| QUESTION NO. P50803-5: Proview pk-986 monitor FCC ije986. I need the value for RT502. |
| RT502 is an inrush-current limiter whose ohms rating is about 8 ohms at room temperature. A possible substitute might be a Thermometrics type CL110. |
| QUESTION NO. P50203-9: Gateway2000 crystal Scan14 Mon014006A0WW monitor has very poor image, display is too dark. Adjusting the screen causes the focus enhanced but still blurry. I checked Q413= BU 2508DF it's ok. |
| Check the CRT for poor emissions (dying CRT). |
| QUESTION NO. P50503-8: Optiquest Q71 monitor powers off immediately. I need the specs on burned voltage regulator Q429. The board is version VCDTS21348-2M. |
| Q429 is 2SC5248, rated 160 Volts, 1.5 Amp, 20 Watts, 150 MHz, DC gain 60-200, Cob 20pF, TO220F case. A 2SC3298 also might substitute for 2SC5248. |
| QUESTION NO. P50203-2: Proview pk-986 monitor FCC ije986. I need the value for R502 and Q502. |
| In the schematic for IJE986, Q502 is a 600 Volt, N-channel Mosfet, such as 2SK2141, 2SK2645, STP7NB60, or IRFBC40; (insulator added as required). R502 (47K) is shown in this schematic as being left open (not installed). |
| QUESTION NO. P42903-5: Samton 45bn monitor. In front panel buttons h size, pallelogram button and pinamp buttons are not working. I replaced DM024 ic, still no change. |
| Check if ultrafast diode D414 is leaky in reverse, or shorted. If D414 is not failing, then check Q412 and its associated components. |
| QUESTION NO. P42503-2: LG Studioworks 795SC monitor Chassis CA-55, the power supply is bad! The TOPxxx and mosfet are burned. Is there an replacement for this TOPxxx? |
| IC903 is TOP223Y; an LG/Goldstar supplier may be able to provide this IC, as LG part# 0IPF223000A. L.J. Enterprises (www.ljecc.com) is also listing TOP223Y, on-line. |
| QUESTION NO. P33103-1: I need to open the service menues of the Philips Brillianc 109p and a Nokia 446 pro monitors. |
| 40 sites containing tv, vcr & computer monitor EEPROM service mode access: http://the-hideout.net/techtalk/phpbb2/viewtopic.php?t=47 |
| QUESTION NO. P40103-9: Compaq v410 model 304U monitor FCC BJMC4A Original problem: LED on the front would just flash amber never turned green. Replaced shorted HOT (C4916) with one that had the same specs with a slightly lower current rating. Now it powers up and displays a picture but I cannot get the horizontal adjustment far enough to the right and it starts to squish the picture the farther to the right I go. Also the new transistor runs extremely hot. |
| Original HOT 2SC4916 I replaced with 2SD1876 which according to the NTE cross are near identical except for the collector current. (10 amps versus 4 amps). I was expecting it to work but degrading the life of the transistor. I have now replaced it with the correct transistor and everything works fine. The NTE cross specs must be inferior or the max. collector current is more important then I imagined. |
| QUESTION NO. P32403-3: Viewsonic G790 monitor has no red, green and blue normal. |
| Trace the color signals to the CRT base PCB and swap two of the colors round (Hopefully the colors will be marked on the PCB). If you now have RED, the tube is OK but the feed is faulty and vice-versa. |
| QUESTION NO. P42303-2: I need the Sony manual part number for a Dell P992 monitor. |
| The number on the P992 service manual is 9-978-704-01. |
| QUESTION NO. P42203-2: LG 910sc monitor. I need the value of burned FET Q901. |
| The LG parts list shows Q901 as 2SK2843, which is a Toshiba 600 Volt, 10 Amp, 45 Watt Mosfet. 2SK2843 is listed as LG part no. 0TF284300AA. |
| QUESTION NO. P41703-4: Dell P1110 monitor (Sony chassis SCC-L22D-A), the CRT heater voltage is muted. Applied external CRT filament supply, the picture appeared, but the screen is too high. |
| Most times in the case of the missing heater voltage, there is usually a dried out electrolytic capacitor or bad inductor coil in the circuit. Check for one or the other. If the capacitor you find is suspected to be bad, you can parallel a known good one across it. If it is bad this should restore heater voltage somewhere around 7 volts DC. |
| QUESTION NO. P42203-6: Optiquest Q71 monitor FCC GSSJ 17001 came from another shop. I replaced the shorted HOT. It is working fine now but too wide. Width control does not work. Pincushion ok. |
| Check or replace D422, Q429, and Q411. |
| QUESTION NO. P42203-1: Philips 15A12F monitor Chassis CM1200. Need value of burnt R3426. |
| R3426 is 4.7 ohms, 1/2 Watt. |
| QUESTION NO. P41703-7: IBM 6558-03n monitor (Sony scc-l04h-a) shuts down deflection code. Need part # or ic # for ic 702(vertical) which is missing. |
| The Sony schematic shows IC702 is LA7841L also check R720 1R 1/2W flame proof resistor and R727 1R 1/2W Flame proof resistor. |
| QUESTION NO. P31903-2: Mag XJ717 Monitor. The HOT shorted, but someone seems to have put in the the wrong type. I need the correct number of Q112. |
| Q112 is a BU2532AL. |
| QUESTION NO. P41503-10: IIyama Visionmaster 400 monitor powers up without a signal connected and shortly goes into power save as expected but the power supply trips out when the PC / test card generator is connected. A chirp is heard just before the power supply shuts down. If the monitor is powered with a signal connected, it shuts down instantly and won't power up again unless left for a few minutes. I changed the FBT and the B+ smoothing caps to no avail. |
| To answer my own question, I eventually found it necessary to change all the low value electrolytic capacitors (about 8 in total values between 1 and 100uf) in the primary side of the power supply. These capacitors checked okay but proved to be faulty by replacement. |
| QUESTION NO. P41503-4: I need a Sony part no. ( 8-xxx-xxx-xx ) for a Sony IC (CXD9164M) from a Dell P992 monitor. |
| The Sony manual lists IC003 (CXD9164MTR) as Sony p/n# 6-700-723-01. (Not "8"). |
| QUESTION NO. P41503-9: LG Studioworks 440Si monitor. I need the value of fried R843 near flyback. |
| R843 is 12K ohms; check if a defective flyback had burned R843. |
| QUESTION NO. P41503-3: Samsung Syncmaster 15GLi CMB5477L monitor was dead. I replaced faulty Q503, 2SC5148 with a 2SC4747 and the faulty Q505, IRF740. I need the value of burnt R507 (in series with the Collector of Q503). |
| R507 is 1.8ohm 2W. Also check C504 22uf 250V and C514 47uf 16V. |
| QUESTION NO. P41403-1: Markvision VC1450D model DA-456 AA monitor Chassis 2970005101. I need the value of burned C441. |
| If its FCC is H79DA-456, a different brand, with this FCC, has a C441 of 220 pF, 2KV. |
| QUESTION NO. P41103-3: Acana Advance 17S monitor FCC IIBUAI, I need value of R425. |
| R425 is 10 ohms, 2 Watts, in the schematic for FCC# IIBUA1. |
| QUESTION NO. P41003-2: Sony 200GS monitor has bad distortion at top of the screen. On cross hatch pattern, instead of vertical lines, it has vertical zigzag lines on top with an approximate length of 1.5cm in each line. |
| Try replacing C573. If C573 is no help, try other 250V capacitors, C572, C575, C524. |
| QUESTION NO. P41003-1: DigiView AT398 monitor has a horizontal line across screen. ICB02 is burned. Can only make out A8172. Believe this is the vertical amp. I do not see any other part that look overheated. |
| This is a TDA8172 also check the diode between pins 2 & 6 and the capacitor between pins 3 & 6 and any resistors in the supply rail 2 and maybe 4 if it is supplied with + & - rails |
| The full number is TDA8172. |
| QUESTION NO. P40803-7: Viewsonic P810-1M / 21HV8SA monitor FCC GSS21001 - Need part numbers/subs and source for D602, D902, D905, R919, and Q902. This is a repair for the common problem of leaking C852 causing shorted D602 and subsequent damage. I am also replacing C852, C601, R602 as well. Any other components affected outside of these? |
| When you replace C852, also repair any damaged PCB traces under C852. D602 = MA167 (similar to 1N4148 or NTE519); D902 = MA4270NH (27V, 0.4W zener); D905 = MA4051NM (5.1V, 0.4W zener); R919 = 390 ohm SMD; Q902 = UN5211AI, an SMD digital transistor (SC-70 case style) with an internal 10K/10K resistor divider. If D905 has gone, I would be concerned about AC voltage continuing past, and possibly also damaging R917 (1.8K), R918 (100 ohm); IC850; and the processor IC901. |
| QUESTION NO. P40703-8: Sony CPD200GS monitor has a normal picture on the bottom half of the screen, but is blank on the top half. I have not located the vertical output IC. Does the vertical IC drive the yoke directly, or is there a transistor stage involved? This looks like some kind of push-pull output failure. |
| IC401 drives the vertical yoke directly. This IC uses dual +/- 15 Volt supplies, so see if either supply is missing, or if either has a bad filter cap; C401, off pin 1; C404, off pin 6. If the supplies are both good, check IC401 itself, and associated components. |
| QUESTION NO. P40403-6: Compaq Pe1120 monitor, the horizontal op and driver j449 was shot. I need info on D310 (PH33D) which is broken in fragments. |
| This device is a Philips BYD33D rectifier, rated 200 Volts, 0.7/1.3 Amp (12A peak); Vf < 1.3V @ 1A.If; Trr < 250 nanoseconds; soft recovery. Some possible substitutes include FR103, HER103, NTE552, and NTE574. |
| QUESTION NO. P31903-10: Acer 7299c JVP7299c monitor, found shorted Horiz. output BU2532AN, replaced with 2SC3997 scoped output, pulse looked ok for 3 sec. blew output. Is this a suitable replacement? Drive circuit? |
| No! Fall time of 3997 is 0.2us and the 2532 is 0.06us. You may wish to check L304 & Q321 possibly burned & shorted. Check all coils and FBT these Acers are boomerangs. They usually come back if you do not check everything. |
| QUESTION NO. P32103-8: Hyundai DeluxScan 17B+ Model HL-7870A monitor is experiencing brightness problems, constant 'dimming' then 'brightening' of display. I replaced defective R502 and R503 but that did not work. |
| Resolder G2 on Tube board and all the other tube connectors. |
| QUESTION NO. P32703-3: Viewsonic 21PS monitor chassis HV4S/H FCC GSS933006 is dead, LED comes on for 1 second then goes out. I replaced C839 and repaired arced trace under it and checked C867 it was OK. Repaired a few bad solder joints, one was cracked at Q583. It powers on now except HV. Degauss works, tube heater works and menu controls will turn led green as will a PC when it is connected. There is power to R588 and R589 but no power to R545. |
| The degauss cable around CRT hits a capacitor on the front of the board and brakes the solder joint. |
| QUESTION NO. P33103-3: Sony GDMF500 monitor with drifting focus and intermittent retrace, all main supply voltages checked ok, suspect focus divider. |
| Before replacing the CP701 focus module, rule out if the CRT has an internal leak-path, which may occur in this model. Detach the CRT board from the CRT, and check with a high-voltage probe, to see if any voltage is leaking into the CRT's focus pins, etc, while under power. If any voltage is seen on the CRT pins while the CRT board is removed, there is an internal leak-path in the CRT. |
| QUESTION NO. P32403-1: Viewsonic g810 monitor Chassis 21VS001(Panasonic), has no horiz sweep, hv is okay. Thin vertical line from top to bottom. |
| Check Q550, Q549, Q881, R890; there may also be a 0.8 Amp microfuse, marked "N11008", which resembles a small transistor, installed in the B+ path. |
| QUESTION NO. P32803-1: Hyundai DeluxScan 5854 monitor. I need a sub for Q303 (YTA 630) transistor. |
| A substitute for YTA630 is IRF630. |
| QUESTION NO. P32703-6: Packard Bell A720 monitor, FCC CKLA720. Is there an alternate horizontal output transistor for 2SC5404? |
| Possible substitutes for 2SC5404 might be 2SC5387 or 2SC5299. |
| QUESTION NO. P31303-3: Dell D1025HT monitor has dim picture and no red color. |
| This was a comman fault of VPS12 IC. |
| QUESTION NO. P32603-2: AcerView 7176ie monitor, the raster (without video input connected) flashed between black (normal) and high brightness. With video input connected, there was video on the screen, but the brightness alternated between normal and high brightness. Clicking sound could be heard as it flashed. G1 on the video board varied from about +33V to -180V when it should be about -45V. I replaced IC201 (TDA8351) and IC102 on the video board, but did not solve the problem. |
| Check/replace the three 450V electrolytics, C3950, C3951, C3952, their associated resistors (R3950, R3951, R3952), and the ceramic cap, C320 = 100pF/2KV. It may be wise to also check the ESR on electrolytics C301, C304, C307, and C330. |
| QUESTION NO. P32403-7: Dell p991 monitor has no video. Replaced Q901 (Irfi9634g) and Q902 (fs5km-18a, replaced with nte2958) both shorted. I checked R934, C507, C644 and C914. |
| Since Q901 and Q902 are for driving flyback transformer T901, I would check if the FBT is bad. Also check gate-protection zeners D906 (10V) and D909 (15V), as well as B+ cap C913, and ultrafast D907. If the G2 voltage is low/missing, check R916, D910, and C919. An FS5KM-18A is rated at 900 Volts, a higher rating than NTE 2958 (700 Volts); is that NTE substitute FET still OK? |
| QUESTION NO. P31403-8: Dell 1600h model D1626HS (Sony Chassis). I need the value of missing Q640 in power supply. R640 is open and looks like C641 has been replaced as there is carbon marks around it. |
| Assuming this model is actually the Dell/Sony 1600HS/D1626HT, Q640 is the dual transistor, MX0841AB-F; you can get this from Sony, as their part# 8-729-041-12. R640 = 0.1 ohm, 1/2 Watt, fusible; C641 = 470 pF/500V, ceramic. |
| QUESTION NO. P32003-8: KDS VS195 EVOKD1900 monitor. I need the part number or suitable cross for Q407 (mosfet). |
| Q407 is IRFS730. Mouser Electronics (www.mouser.com) lists IRFS730B, or else you can use IRF730 with an insulator. Also check or replace D409, D410, D411, D412; Q425; R497, R498; IC401; and the flyback transformer. |
| QUESTION NO. P31703-1: TVM AS6S monitor. I need the values of Q424, R495 and Q001. |
| In my schematic, Q001 = IRF630, Q424 = 2SC3117, and R495 = 10K ohms. |
| QUESTION NO. P31003-3: Compaq Presario MV520 monitor. I need the value of burned R903 located between the + of the mains cap and Collector of Q902. |
| R903 is 33K Ohms. |
| QUESTION NO. P22603-4: CTX VL950T FBT (Sampo FM1037D) monitor. I need a sub or specs on the FBT within the UK. |
| Sampo FBT = FM1037D = 47F13-07205, FBT is part# 47F13-0720s £26.44 inc VTA/P&P at Isotronic. 173 Martindale Rd, Hounslow, Middlesex, TW4 7EZ, 0208 577 6577 Tel, 0208 577 6657 Fax, 07939 273252 Mobile. |
| QUESTION NO. P31103-1: Sony GDM200ps FCC AK8GDM200PS monitor is black screen when turned on, the power LED turns solid green for a few seconds and then goes off and immediately after that LED turns amber and blinks. This happens irrespective of whether the vga cable is connected or not. It is on for 1.5 and off for 0.5 sec. |
| That LED flash-time sequence implies a horizontal/vertical deflection failure, or thermal protection. The most common cause of deflection problems in this (N3) chassis, is a defective IC007 (CXA2043Q) chip, Sony part number 8-752-078-46. |
| QUESTION NO. P30603-8: Gateway EV700 Monitor (LG - CA65 chassis) has very low brightness. It does control via the OSD menu. All voltages are correct, including the CRT filament voltage and filaments are properly lit. What should the G1 voltage be for proper brightness? The G1 voltage in this unit is controlled from the OSD processor. I have a voltage of neg 15v at maximum brightness and it goes further negative as I lower the brightness. If I force the circuit more toward 0v or positive voltage, the unit seems to get a near normal brightness level. This unit has no G2 level control on the fbt, so there seems to be no other point at which the brightness level can be set. I have checked this unit thoroughly for all possible bad caps and solder connections. |
| This model the G2 is controlled by the Micon and is set by software and an interface. |
| QUESTION NO. P21703-6: KTX GAG664SG monitor keeps blowing the line transistor after 2 hours. I changed 2SC3886 and FBT. |
| The drive is rough for some reason, a capacitor open the oscillator sparky etc. Check for a dry joint on a 470uF filter on the 12V line feeding the oscillator. |
| QUESTION NO. P30503-5: Acer 77c monitor has severe hourglass. The components around IC202, TDA8351, the vertical IC, did not look burned or unusual. I replaced IC202 anyway, but the problem was still there. I measured many transistors in the horizontal area in circuit and they seemed to be good. |
| Check C323 = 33 uF/250V. |
| QUESTION NO. P30503-6: CTX 1760LR monitor. I need value for C333 (someone else removed from mb.) |
| C333 as 10 uF, 250 Volts. |
| QUESTION NO. P30503-7: Dell Ultrascan P780, chassis SCC-L29K-A: monitor clicks on power up and then green light will turn amber and flash. HOT and all other components tested OK. |
| HV/+B failure Blink Amber on 0.5 sec off 0.5 sec. H stop or V stop (included S-cap Blink Amber on 0.5 sec off 0.5 sec. ABL Failure Blink Amber on 0.5 sec off 1.5 sec. Aging/self-test Blink Amber on 0.5 sec off 0.5 sec Blink Green on 0.5 sec off 0.5 sec. |
| I think the H stop or V stop is Amber on 1.5 sec: off 0.5 sec. |
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