I assume you've already checked test mode, and no problems are reported.
I also assume you've verified all the EPROMs (code and gfx) and checked out all the RAM you can see with your Fluke.
Yes?
I assume you've already checked test mode, and no problems are reported.
I also assume you've verified all the EPROMs (code and gfx) and checked out all the RAM you can see with your Fluke.
Yes?
Um, perhaps it's somewhere around there... but really doubt it's the PF ROM select. That's because it's always selected (see attached schem clip)...
That said, I would be looking at things of the left side of that sheet of the schematics (playfield generator), assuming all the EPROMs are good, and all the RAM checks out.
I place my bets on bad RAM @ 4K or bad TTL at 6K or 4L. Because you're getting complete and good tiles... just the wrong ones.
well, just got the digdug board, and the 0214 Custom is pretty rough, also had a "broken" pin... going to carefully clean and try to re-install. going to need to order some good replacement sockets, not feeling machine sockets lately.