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Repairing BenQ 17″ LCD Monitor
By Jestine Yong on January 31, 2008
I came across a common fault problem in BenQ 17″ LCD Monitor. The problem is have power but no display. Once you has opened the LCD cover, check the pico fuse for open circuit (very common), the push pull transistors C5707 for short circuit and the Buck royer circuit p-channel fet FQU11P06 also for short circuit too. For your information, if you can’t get the FQU11p06 you can always use FU9024N as a replacement. Resolder all the high voltage transformer pins and replace the components above and I’m sure you will bring back the life of this BenQ 17″ LCD Monitor.
You may go to this fairchild semiconductor website to download the spec of the FQU11P06 P-channel FET.
http://www.fairchildsemi.com/ds/FQ/FQU11P06.pdf
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Sergio
October 26, 2014 at 1:00 am
Hi Justine
I have a problem with my Benq T720 model Q7C3
it turns on and has green LED comes, but gives no picture
some clue?
Jestine Yong
October 26, 2014 at 5:06 pm
Did you get any dc voltage at the pin of the inverter ic?
Jestine
Cesar T.
October 26, 2014 at 12:12 pm
Hi Jestine...i'm having same problem as a guy named Michaels had, and maybe you haven't seen his question:
I appreciate your help and would like to thank you in advance!
MichaelS
February 17, 2012 at 5:24 pm
Useful web page and advice, congratulations and thanks. Question: BENQ FP71V monitor, L0Y02.A10 power board, a Q7C4 variant (usual one is .A02). Have circuit diagram for A02 version, similar but not identical (A10 has 2+1, not 4+1, transformers; most of board has same component codes like IC701). Symptom already described here: powers down intermittently with pilot light off. If cold, will usually work correctly for a few minutes or hours; if warm will probably power up not at all, or briefly. No capacitor bulged or leaking gunge, all e-ESRs (except 1uF) below 2 ohms. For these problems I think you have said if voltages normal, probably logic board; otherwise likely C, R, or joint on power board. Additional visual symptom: 3-pin 3.3V regulator, IC701, LD1117, powered from 5V line, is soldered flat to bottom of PCB. The top of the board above IC701 is very heat-blackened (not totally charred, and no metal traces there, partial short not likely). Is this normal for these boards, or does it pin down the diagnosis further? By the way, board doesn't seem to have 2SC5707 anywhere (nothing looking like any 15W transistor, just 1 big heatsinked FET, 2 heatsinked diodes). Lots of tiny 2mm SM transistors on bottom of PCB near transformers. Thanks
Jestine Yong
October 29, 2014 at 10:11 pm
Hi Cesar,
What is the complaint of your Monitor and what have you checked? Is the output voltages from the power supply good?
Jestine
Sergio
October 29, 2014 at 3:18 am
Hi Jestine
You are speaking of ic751,right?
I dont have dc voltage between pins 8 and 9
Jestine Yong
October 29, 2014 at 9:42 pm
I can't remember because I don't have the schematic or the monitor with me. What is the part number?
Jestine
Gerber
December 19, 2014 at 6:07 am
Hello Jestine Yong.
Do you have a schematic for the monitor Benq FP71G, model Q7T4
admin
December 19, 2014 at 11:26 am
Hi Gerber,
Sorry I do not carry any schematic. try eserviceinfo.com
Jestine
Sergio
October 30, 2014 at 2:39 am
Hi Jestine
I dont have dc voltage at the pin of the inverter ic
Jestine Yong
October 30, 2014 at 8:41 pm
In this case you may have to trace backward to see where the dc supply have gone missing. It could be due to an open pico fuse.
Jestine
Sergio
December 22, 2014 at 9:00 pm
Hi Jestine Yong
after checking the circuit before the ic 751
I found that the problem was the fuse that was open (MS 3A 125V).
fuse replaced and the Benq gained new life.
thank Jestine
admin
December 23, 2014 at 9:09 pm
Hi Sergio,
Congratulation.
Jestine
Sergio
October 30, 2014 at 2:41 am
I think is TL1451AC
Sergio
October 31, 2014 at 5:03 am
Hi Jestine
Ok i go check
Ricardo
March 19, 2015 at 12:56 am
Hello Jestine Yong
i have a new problem in Benq FP71G+ monitor
the monitor is always restarting,the monitor is off in the power button,but
after a few seconds the monitor turns on alone and after that is constantly restarting (turn on/off),can you help me?thanks
Jestine Yong
March 21, 2015 at 10:30 am
HI Ricardo,
If the output voltages are good and stable this means the MCU/Flash Rom IC is the cause of the problem.
Jestine
Deepa
September 11, 2015 at 11:21 pm
I have a Benq DV2050 model, I have misplaced the power cord. Where can i buy the power cord? It has 3 triangular holes for AC-Inlet. Thanks!
Jestine Yong
September 12, 2015 at 9:27 am
HI Deepa,
Try check from the computer shop.
Jestine
vishnulal
October 3, 2015 at 1:06 am
My benq ET-0005-NA power supply bord STR broken plz tel this STR Number
Jestine Yong
October 5, 2015 at 10:34 am
Hi Vishnulal,
Since I do not have the schematic and there is no same model of lcd monitor with me in my workshop thus I can't find the part number. You may have to search for the schematic.
Jestine
Fikret
February 7, 2016 at 6:49 am
Hi Justine
48.l0y02.a02 Power Board is defective.
702 L +5v - internal 7001 +3.3 I have
Benq on-screen acinca beer( missing out)
Justine's opinion, may be where the fault is.If you answer I'd appreciate it.
Jestine Yong
February 9, 2016 at 10:48 am
Hi Fikret,
First, does the power board produce the 5 volt and the 14 or 19 volt?
Jestine
Wajid Malik
January 3, 2018 at 1:05 am
Hello BenQ g700ad LCD monitors on off on off 20 menat on please help me