iesposta Posted March 10, 2012 Share Posted March 10, 2012 Any guesses on why my 7800 displays Beef Drop VE like below? Adding Longhorns video board by LittleJoe showed no change except a much clearer picture. Scramble doesn't work at all. Could it be RAM corruption ( bad RAM )? Electrolytic caps? I'm out of ideas. Moon Cresta works 100% Everything else is fine. Removed cap and Robot Tank and Supercharger work! Recapped power supply, and checked voltage regulator - ok. Ballblazer is ok. Food Fight is ok. Pole Position II is ok. All 2600 operation is ok. Cart port sanded & cleaned and resoldered. Thanks for any suggestions. 1 Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted March 10, 2012 Share Posted March 10, 2012 Is the junk on the screen always in the same places? Quote Link to comment Share on other sites More sharing options...
iesposta Posted March 10, 2012 Author Share Posted March 10, 2012 Is the junk on the screen always in the same places? Yes. Always the same places. And animated too like Yars' Revenge. Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted March 10, 2012 Share Posted March 10, 2012 Try resoldering the joints on the 2 RAM chips and MARIA. Quote Link to comment Share on other sites More sharing options...
iesposta Posted March 10, 2012 Author Share Posted March 10, 2012 Try resoldering the joints on the 2 RAM chips and MARIA. Thank you for the suggestion. No change. Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted March 10, 2012 Share Posted March 10, 2012 Does the system work OK with the larger games like Commando, Alien Brigade, Scrapyard Dog, Rampage, Midnight Mutants, Jinks etc? Quote Link to comment Share on other sites More sharing options...
iesposta Posted March 11, 2012 Author Share Posted March 11, 2012 I only have the 6 games listed in my original post, and The XM ordered. "EP" - these were the original 5000 made in El Paso Texas in mid 1984. "AT84" - early batch still with Atari Inc. "AT85" - early batch now with Atari Corp "A1" - initial models still had the expansion interface "A1" - later models lost the expansion interface "A3" - next run of the 7800 units "X" - final run of 7800 units? -My serial number is an X so that must be why some home-brews don't work!!!! I'll be looking to get an A1... Will the XM use its memory? That might help. Quote Link to comment Share on other sites More sharing options...
iesposta Posted March 18, 2012 Author Share Posted March 18, 2012 Got a new 7800 today! This is Serial Number "A1 87" without expansion interface. - Beef Drop is perfect. - Scramble is perfect. - 2600 operation is perfect. - Robot Tank runs without modification. I read something about a newer TIA chip? If the Serial Number X 7800 is the final run... Maybe that is the reason some home brews won't run? Now, do I keep it RF, or move AV upgrade from lousy Serial Number X 7800? Decisions... Decisions... Quote Link to comment Share on other sites More sharing options...
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