Build Your Own Arcade Controls Forum

Arcade Collecting => Miscellaneous Arcade Talk => Topic started by: eggedd2k on June 16, 2005, 03:50:32 pm

Title: Is it possible to repair faulty jamma pcb's
Post by: eggedd2k on June 16, 2005, 03:50:32 pm

there are loads of these on ebay - http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=3945&item=6186793215&rd=1

is it possible to repair jamma pcb's without any super electronics knowledge/skills?

Title: Re: Is it possible to repair faulty jamma pcb's
Post by: pcb on June 19, 2005, 02:09:58 pm

Your guess is as good as anyones.  They may have simple problems, they may have extensive problems.

That being said, I wouldn't buy them, and I repair boards. :)

Title: Re: Is it possible to repair faulty jamma pcb's
Post by: RayB on June 19, 2005, 10:02:04 pm

I would email the guy and ask what error he is seeing. From the screens-shot, looks like everything passed. Maybe the guy has theboard in test mode and he doesn't realize it! (usually requires flipping a dipswitch!)

Title: Re: Is it possible to repair faulty jamma pcb's
Post by: paigeoliver on June 20, 2005, 06:37:53 am

Newer boards can be a lot harder to fix due to miniaturization and big surface mount chips. What happens when you finally troubleshoot the problem and it is an 80 pin surface mount chip. I'd say about 1 percent of arcade game guys can solder well enough to replace one of those.

Pre-Jamma stuff also tends to be easier to diagnose, since most faulty JAMMA boards I have seen do one of two things, either display nothing, or display garbage. While most classic boards tend to still do stuff when they have problems.

Faulty classic boards I have owned have done all the following.
Played the game with garbled sprites, and/or backgrounds (lots of games)
Had something missing from the display (score, etc) (Rally-X before I began repairs)
Had missing sprites (Space Pilot)
Had funky vectors (Star Wars)
Added strange things to the background. (Circus Charlie)
Had incorrect colors (Rally-X)
Spelled EVERYTHING wrong (Sega Turbo).
Incorrectly scaled objects (Sega Turbo).
Bad sounding audio (A LOT of boards)
Missing shots (Space Firebird)
Booted to garbage or blank screen (Track & Field and a few other Konami titles, only a SMALL percentage of the defective boards I have had)

Meanwhile as for JAMMA boards.
90+ percent of the defective ones have booted to garbage or not displayed anything.
One (TMNT) constantly reset after self test.
One (Last Duel) had missing audio.