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Old 09-15-2022, 08:21 PM   #1
mikey5791
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Smile AOC 2219Vg white screen

Hi,
Got this used AOC monitor from a cybernet cafe complain of it displaying just white screen.
I checked the power board Changhong 715G2510 -1-4 Ver:B and detected 5vdc (both red wires) at output pin CN902. In addition, i also detected 5vdc (both red wires) at the input pin CN201 of the smaller card.(controller card?)
Next i checked the t con board but found only about 0.02vdc at the 5V test point. There is no other voltage detected on the t con board.
The only fault suspect is the controller card. My suspect could be wrong and hope someone experience can point me in the right way.

Can someone kindly assist and guide me in solving this mystery of the missing voltage. I am looking forward to learn and diagnose from the basic step if time permits.
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Old 09-16-2022, 04:35 AM   #2
lotas
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Default Re: AOC 2219Vg white screen

The problem is rather in the Q601 -Mosfet transistor, power is supplied to the T-con matrix through it.
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Old 09-18-2022, 07:22 PM   #3
mikey5791
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Smile Re: AOC 2219Vg white screen

Hi lotas,
Thanks for your reply.
Fyi, i had another working power board and controller board for this AOC 2219Vg (but cracked screen) which i swapped on the display panel. Too bad the screen still shows white screen.
Any other suggestion or assistance in getting this monitor fixed is highly appreciated.
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Old 09-19-2022, 03:46 AM   #4
lotas
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Default Re: AOC 2219Vg white screen

Well then, the problem is in t-con, is there 3.3v at this point?
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Old 09-20-2022, 08:10 PM   #5
mikey5791
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Smile Re: AOC 2219Vg white screen

Lotas,

There is no voltage on t con board test point 3VDD or on 5V test point.
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Old 09-21-2022, 01:58 AM   #6
lotas
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Default Re: AOC 2219Vg white screen

Check fuse.
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Old 09-21-2022, 02:16 AM   #7
mikey5791
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Smile Re: AOC 2219Vg white screen

Lotas,
The fuse at F1 has continuity and there is no burning mark seen anywhere on t con board.
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Old 09-21-2022, 02:41 AM   #8
lotas
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Default Re: AOC 2219Vg white screen

If there is 5v and no 3v, then it remains to replace IC3
1117 33.
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Old 09-21-2022, 10:40 PM   #9
mikey5791
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Smile Re: AOC 2219Vg white screen

Lotas,
But in my case if there is no 5v or 3v on the t con board, is it likely Q601 mosfet transistor on both the controller board is bad?
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