Repairing BenQ 17″ LCD Monitor

By on January 31, 2008

BENQ LCD MONITOR

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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453 Comments

  1. 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?

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    • Jestine Yong

      October 26, 2014 at 5:06 pm

      Did you get any dc voltage at the pin of the inverter ic?

      Jestine

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  2. 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

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    • 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

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  3. 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

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    • 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

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      • Gerber

        December 19, 2014 at 6:07 am

        Hello Jestine Yong.
        Do you have a schematic for the monitor Benq FP71G, model Q7T4

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        • admin

          December 19, 2014 at 11:26 am

          Hi Gerber,

          Sorry I do not carry any schematic. try eserviceinfo.com

          Jestine

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  4. Sergio

    October 30, 2014 at 2:39 am

    Hi Jestine
    I dont have dc voltage at the pin of the inverter ic

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    • 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

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      • 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

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        • admin

          December 23, 2014 at 9:09 pm

          Hi Sergio,

          Congratulation.

          Jestine

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  5. Sergio

    October 30, 2014 at 2:41 am

    I think is TL1451AC

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  6. Sergio

    October 31, 2014 at 5:03 am

    Hi Jestine
    Ok i go check

    Likes(0)Dislikes(0)
  7. 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

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    • 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

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  8. 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!

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    • Jestine Yong

      September 12, 2015 at 9:27 am

      HI Deepa,

      Try check from the computer shop.

      Jestine

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  9. vishnulal

    October 3, 2015 at 1:06 am

    My benq ET-0005-NA power supply bord STR broken plz tel this STR Number

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    • 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

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  10. 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.

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    • 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

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