Viewsonic VA1912W's No Blue

[toddstidham1]

Hey all, long time lurker, first time post. I've started fixing a batch of Viewsonic LCD Monitors. I found the power board with bulged blown caps (capxon greenies, 2x220uf, 1x2200uf and 1x1000uf) and I'm replacing them with same spec Panasonics.

My problem is, the one is working now, but there is no blue color on the LCD. In the OSD Menu, all colors are set to 50% but adjusting them does nothing. This is the second one I recapped, the first I think also has a blown inverter chip for the ccfl bulbs, the screen stays black on that one (though the power LED no longer flashes on and off dim). When I used this second power board in the first monitor, I get the same screen with no blue color.

Anyone see this before? Is the video board blown on both?

[selldoor]

Re: Viewsonic VA1912W's No Blue

Should there be blue on the osd? and is it missing on there.
Usually a missing colour is a faulty vga cable or socket - did you use the same cable on both?

[ben7]

Re: Viewsonic VA1912W's No Blue

Try clearing the EEPROM on the mainboard, I had a Syncmaster who had a corrcupted EEPROM, which caused the picture to be black and red

[toddstidham1]

Re: Viewsonic VA1912W's No Blue

Thanks for the replies guys.

Yea, the OSD is in full color, but there is no blue color available. I get a windows desktop but it's just greens and reds. I did use the same laptop and video cable for both tests and you make a good point. I'll try the setup on a known working monitor tomorrow. Perhaps the problem is with the laptop and/or vga cable.

ben7, I'm not sure I'd know how to do this. Is it shorting certain pins while powered on? using the OSD menu to reset defaults? Any elaboration would be helpful!

Thanks, Todd

[Peter9DO]

Re: Viewsonic VA1912W's No Blue

Here is a link to the service manual for the model. Good luck my friend!

https://cdn.badcaps-static.com/pdfs/...f5aba57d69.pdf

[toddstidham1]

Re: Viewsonic VA1912W's No Blue [solved]

DOH! and LOL. The laptop's video port was the culprit! I used a different laptop and the monitor is working fine.

I've since recapped my third monitor and it's also working great. Three more to go. Thanks guys!

[Peter9DO]

Re: Viewsonic VA1912W's No Blue

Nice!

[toddstidham1]

Re: Viewsonic VA1912W's No Blue

So just to recap (pun intended!), I was able to fix five out of six monitors and all are working great. The sixth one did start up after the initial recapping, but then it made a snap noise and the backlights and video went out. I've checked the fuse (good) but there is simply no power output from the power board to the video board or to the backlight inverter. I suspect the transformer itself went but at this point I don't really care. Saving 5 out of 6 from the trash heap is pretty good. I'll hold onto the LCD screen itself (which still works fine) and just scrap the rest.

Again, thanks to everyone that responded.