Administrators Arcade King Posted September 8, 2011 Administrators Share Posted September 8, 2011 (edited) Problem: Game will start up fine and run however once its been on for awhile if you try to turn it back on game goes into a watchdog reset loop. Common problem specially with Shaq Attack. If you leave the game off for 5 minutes and restart 99% of the time it will boot up. Fix: I found replacing the 2 tantalum caps at C20 and C21 (1uf 50v) with common 1uf 64v electrolyte caps solved the problem beautifully. Before After- Note positive is make with a + in pic. Other causes/fixes from what I've read and heard (can't verify) Bad 74HC123 @ U11 (Harris Branded) Rom revision upgrade. As you can see the in the second pic the chip is Harris and was fine so its worth changing the caps before worrying about the IC. Possible causes: Over voltage. Edited September 8, 2011 by Arcade King Link to comment Share on other sites More sharing options...
andykmv Posted September 8, 2011 Share Posted September 8, 2011 hmm , do you know of a supplier fo those axial tantalums ? Link to comment Share on other sites More sharing options...
Administrators Arcade King Posted September 8, 2011 Author Administrators Share Posted September 8, 2011 Never looked, Electrolytic caps worked fine and is what I had on hand. Link to comment Share on other sites More sharing options...
andykmv Posted September 8, 2011 Share Posted September 8, 2011 yeah i havent looked either. have to do some searchin as i have a few boards with these on. ---------- Post added at 09:16 PM ---------- Previous post was at 08:59 PM ---------- hey trav, can you read the manufacturer markings on the original axial cap ? just thoought it would be a good exercise to chase down the part species and an equivalent from digikey (theyve got lots of the axial tanty caps)! Link to comment Share on other sites More sharing options...
Administrators Arcade King Posted September 8, 2011 Author Administrators Share Posted September 8, 2011 Personally mate I've always avoided using tantalums , seen to many go pop and cause damage for my liking. That's just me though :) Will have a look. Link to comment Share on other sites More sharing options...
andykmv Posted September 8, 2011 Share Posted September 8, 2011 interesting new avitar! - the "where'd that damn clip go....." pose ? :lol Link to comment Share on other sites More sharing options...
sparkythepinmonkey Posted January 29, 2017 Share Posted January 29, 2017 Possible causes: Over voltage. I always replace the shitty 500R pot on the regulator board with a Cermet type, to try & alleviate any +5v 'wandering'. Regardless of whether it has failed or not. I won't take the chance. ;) Link to comment Share on other sites More sharing options...
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