Scramble keeps resetting?!

[retroshaun]

I just picked up a Stern Scramble today - its a little grubby (been sat in a very bad garage for years) and I'm actually surprised it works at all! However, there are definate problems...

 

The main issue is that the game keeps resetting. Sometimes you can start a game and after the first big mountain the game either completely resets or the screen corrupts (fills with pink and some of the rocket towers from the final stage), THEN resets. Sometimes it runs in attarct for a little while before resetting, other times it sticks on the grid pattern.

 

Not having looked at this at all I guess its either a PSU issue or a board fault. Whats the best starting point? Measuring the PSU output? Do I test on the board test points, chips or straight at the PSU outputs? I'm relatively inexperienced with repairs but know the basics. Its its teh PSU then I guess a switcher is a good fix?

 

Aside from that, the next issue is theres no sound - maybe the above (PSU?) problem is related, or the wiring as it look a little messy. I do have speaker hum / buzz though so I guess its getting power.

 

Thanks for any assistance.

[[d2f]Iggy*SJB]

Shame someone took such bad care of that game.

 

Best thing I can suggest, is to give it a really good cleaning. Check to make sure that all chips are seated properly, and secure any loose wiring.

 

Wish I could find one of those.... I love that game.

 

Good luck with it!

[atarian63]

I just picked up a Stern Scramble today - its a little grubby (been sat in a very bad garage for years) and I'm actually surprised it works at all! However, there are definate problems...

 

The main issue is that the game keeps resetting. Sometimes you can start a game and after the first big mountain the game either completely resets or the screen corrupts (fills with pink and some of the rocket towers from the final stage), THEN resets. Sometimes it runs in attarct for a little while before resetting, other times it sticks on the grid pattern.

 

Not having looked at this at all I guess its either a PSU issue or a board fault. Whats the best starting point? Measuring the PSU output? Do I test on the board test points, chips or straight at the PSU outputs? I'm relatively inexperienced with repairs but know the basics. Its its teh PSU then I guess a switcher is a good fix?

 

Aside from that, the next issue is theres no sound - maybe the above (PSU?) problem is related, or the wiring as it look a little messy. I do have speaker hum / buzz though so I guess its getting power.

 

Thanks for any assistance.

Check your p/s voltages (should be marked on the board somewhere,)see manual http://arcadeconnection.serverbox.org/arca...mble%20(EN).pdf

Power supply probably has dried up caps or the power board does, usually you can adjust voltages on the power board assuming it has one.

also as the previous poster mentioned, check cables(reseat) and then board connections between boards (reseat), then chips. Do these one at a time and recheck or you may create a bigger problem that you already have.

 

Cheers!

Edited December 21, 2008 by atarian63

[Cassidy Nolen]

I would guess a low voltage condition as well. Given that it is not minty fresh to begin with, swap in a switching power supply and eliminate a poorly-designed (don't hate me, its true) power supply and start with clean voltages. Then I would say take a look for a flow chart on board function, could be a watchdog tripping or something goofy from resistance in the sockets on the board. Any visible board damage or water/acid marks?

 

CN

[Cassidy Nolen]

http://arcadeshop.com/pics/stern-ps-kit.jpg

 

Heres the quick and dirty way to do it. 40 bucks and its eliminated as a problem.

 

CN