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General discussion

Plasma, VGA great, component and composite terrible

Apr 2, 2010 5:02AM PDT

I have a JVC GM p420 GCE. Its an Enhanced Definition Monitor.

The barebones model came with just the VGA board installed. But since then the component and composite board has been installed. I bought it after all this, second hand, so I have no idea who installed the board.

I have a good bit of knowledge when it comes to electronics and I have checked this monitor as best I can but cant see the problem.


If I connect something through VGA the picture is crisp and sharp. When nothings connected and I set the screen to VGA mode it stays perfectly black.

If i connect through component cables there is ghosting or feedback visible on screen. The amount depends on the cable quality.
If theres a dark image on screen the bottom half of the screen throws up black pixels. Also, the majority of the time there is a white pixel storm in the bottom right hand corner.
When i switch to component mode with no cables plugged in i get the pixel storm.


If i connect through composite, well its just a terrible, terrible picture.

So, considering the VGA is solid, i thought it must be something to do with the other board. I checked it, and all the grounding locations, and it seems fine. No bad caps or visible problems.


Has anybody any idea what the problem might be? Or what i should be looking for.

I tried resetting the V sync pot, but it didn't do anything.

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