Viewsonic VX2245WM - White screen

[ndawgtkd]

Just completed a LED conversion on this monitor (https://www.badcaps.net/forum/showthread.php?t=55502). Display was working before the conversion, and at various points that I tested throughout, however upon completion I have no video output. I tried 2 DVI cables, to be sure. I am unable to view source selection or the menu.

I tested various vcc points on the board running the length of the LCD, and they all read around 3v, however the outputs on each channel (1out1, 1out2, 2out1, 2out2....etc) each read around -150mv. I do not see a fuse on this board at all.

Logic board model number: A170E2-E03-H-S6
LCD board: A220Z1-Z01-H-X

Pictures of boards: http://imgur.com/a/8lHES

Any advice would be appreciated.

[knoxrebel]

Re: Viewsonic VX2245WM - White screen

Top flex cable damage?

[ndawgtkd]

Re: Viewsonic VX2245WM - White screen

I have carefully inspected both flex cables from the logic board for damage as well as all of the hot-knifed connections to the LCD and see no damage. Any advice?

[sean0118]

Re: Viewsonic VX2245WM - White screen

So there's no video output, but does the LED backlight come on?

I don't know this specific monitor, but does the main control board have a line on which it senses the status of the backlight? I suspect there is a line somewhere that needs to be pulled high/low.

[ndawgtkd]

Re: Viewsonic VX2245WM - White screen

I just converted it to LED, and they are activating. Before I started this project the LCD would display even though the backlights would not turn on. Please see previous thread for pinouts and voltage readings. I'm not sure if one of them needs to be pulled low, however if I disconnect the LED control board the LCD still does not have any video out.

[ndawgtkd]

Re: Viewsonic VX2245WM - White screen

Plugged it up again and RTD2553v chip is physically hot. What might cause that?