Re: Viewsonic VA912 logic board issues



I am NOT confused. The Inverter board is the one with the main voltage input. The one on the right in my picture (the logic board) is the one being faulty. I can guarantee that. As I said in my original post, I have two identical monitors. One is now working and the second one is not. I have been swapping parts between the two and pinpointed that the logic board is the culprit. With the good logic board, the monitor works with any one of the inverter boards. However, with the bad logic board, the monitor does not work with either...

Re: Viewsonic VA912 logic board issues

The inverter board and the logic board are in the picture.

The inverter board has no problem as it works when coupled with a good logic board.


I found the schematics around the connector between the two boards (attached). Pins 1,2 are 12Vcc, Pins 3,4 are GND and Pins 5,6 are 5DVCC and all appear normal. I therefore tried to measure pin 7 and pin 8 in the connector. I doesn't seem to get a proper reading for both pins no matter I tried a good or bad logic board (zero readings). But I am pretty sure the good...

I have two broken VA912 with same symptom of black screen.

I replaced the caps on the inverter board for the first one and it then worked right away.

However, when I did the same on the second one, symptoms remains. I swapped the parts with the first monitor. I can conclude that it is due to the main logic board.

I can see the image when I shine light on the LCD panel. It has to be the backlight not coming on.

I examined the board and could not find amy bulged caps. Any pointer where I should look or caps that I should change?