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PCE RGB output help

Started by gojira1954, 10/26/2015, 06:50 PM

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gojira1954

Hello,
I've modded a white PCE from stock with a THS7314 amp, I'm getting sound out OK but no video at all.
I've checked my monitor with a known good source, and checked my wiring for mistakes - all OK.
I removed the amp and connected the RGB points direct expecting to see a dull image but still nothing.
I'm not getting any voltage on the RGB lines - should I?
Can I test the C6260 IC for voltages?
I only have a multimeter, no scope or probe.
Any help greatly appreciated :)

thesteve


wilykat

What display are you using?  Some are picky about sync type, some are more forgiving.

I have a Commodore 1084 and it refused to work without separate H and V sync so I had to use sync stripper out of composite video to get that monitor to work with the RGB.

gojira1954

I'm using a pvm, I have other consoles including PCEs that work OK so the monitor I'm using works with the sync outputted.

@thesteve - when you say got sync how can I measure it?
What values am I looking for on the RGB & sync lines please?

pdiggitydogg

Where are you pulling sync from? On the expansion port (I'm assuming you grabbed your signals there) there is a pin near those for rgb that is labeled 'sync' and there is another for composite video.
Some have better luck with composite video as sync.

gojira1954

Thanks for the replies...
I'm taking sync and RGB signals from the expansion points - I'm not tapping into composite video, I'm taking the sync signal.
If it was a sync issue, which I don't think it is, I would see a rolling messed up picture? But I get nothing at all, no flash on the screen when powering up.
The console is running as I can hear the hucard audio when a game is powered up, just a completely blank screen :/
I would like to rule out failure of the C6260 IC but again I ask pretty please how/can I do this by measuring voltages?