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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: gojira1954 on October 26, 2015, 11:50:07 AM

Title: PCE RGB output help
Post by: gojira1954 on October 26, 2015, 11:50:07 AM
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 :)
Title: Re: PCE RGB output help
Post by: thesteve on October 26, 2015, 12:11:58 PM
got sync?
Title: Re: PCE RGB output help
Post by: wilykat on October 26, 2015, 03:58:53 PM
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.
Title: Re: PCE RGB output help
Post by: gojira1954 on October 26, 2015, 06:52:06 PM
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?
Title: Re: PCE RGB output help
Post by: pdiggitydogg on October 26, 2015, 10:36:30 PM
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.
Title: Re: PCE RGB output help
Post by: gojira1954 on October 27, 2015, 01:08:26 AM
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?