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LCD Monitor is black... blowing transistors

Product is a Benq FP931 19" Monitor

LCD power light is on and green (getting signal from the video card) but the screen is black. I can see my desktop when I shine a light onto it...

I took the monitor apart and nocitced 5 blown capacitors.. This leads me to believe that the backlights may be ok.. but will for sure when the capacitors are replaced.....

I replaced the capacitors and plugged the monitor back in. Immediatly one of the new capacitors popped, smoked and was leaking some stuff.... so Im sure that i need to test some fuses and transistors.. problem is, Im not exaclty sure which is for what and how to test properly.

Thanks for any help...

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  • bmelnyk Oct 02, 2008

    ok I may have installed it backwards.. honestly im not sure exactly what I am doing.. how can I tell which way is not backwards.. the caps i took out were 25volt 1000uf.... i made sure they were the exact same..

    thanks for the response



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Bulging or "blown" electrolytic capacitors are a common problem with LCD monitors. If you replaced them with correct parts (voltage rating) then one of two situations comes to mind:
1. Electrolytic caps are polarized, if you install them backwards they will blow quickly.
2. The voltage the circuit provides exceeds the rating of the cap. A 5 volt cap in a 12 volt circuit will blow quickly. The voltage regulation circuit may not be working.
Monitor Mike

Posted on Oct 02, 2008


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