Problem with my NBA Jam - weird flickering crash

[sixteenbits]

Hi all. Great forum here, glad to have found it!

I'm hoping someone can point me in the right direction with a crash I'm having with my NBA Jam cabinet. It's not an official Midway cab, but it's fairly well built.

Here's the problem: During play (or more typically, a few seconds after turning the machine on) the screen will begin to flicker. It looks like a few lines of gray static. A soft, repeated "tick-tick-tick-tick-tick" can be heard coming from the monitor. I lose all game audio too, so it's as if the game crashed outright. Sometimes the game will reset, but lately it's just been hanging at the flickering. I'll turn it off and then on again, and it will either do it again after a few seconds or be fine for the next hour or two.

For the last week, most of the time I'll play full games and leave the machine on the attract screen with no problem. During normal play like this everything works great - no issues with video, audio, or controls. But today and yesterday it's been doing the weird flickering crash more and more. It used to automatically reset but now it's happening consistently a few seconds after boot up and staying on the flickering until I turn the machine off.

For a while I thought it was the reset / CMOS options button (located inside the machine) which had one wire that wasn't connected very well. But I disconnected that switch and made sure the wire had good contact and I still get the problem. But that appeared to fix it in the past. I'd fix the wire's connection, plug the machine back in, and play a game no problem. But not today.

If it's any extra clue, one time I went to the dip switch diagnostic and got the crash. As far as I can tell the dips are set fine, however.

Thoughts? I'm stumped!

[sixteenbits]

I *think* I may have fixed it. There was a ground wire that was in a bad spot. Since fixing that, the issue hasn't occurred. Sound like something that could cause such behavior?

[sixteenbits]

Nope

It was doing the flicker crash right on boot all afternoon. I made the grounding fix. Problem immediately went away. Play 3 full games, no problem. Left the game on the attract screen for about 30min. Now it's doing it again!

Stumped...

[sixteenbits]

Solved!

Received advice that the T-unit Midway games are prone to issues with unseated ROMs. Took the main and sound board and gently pressed down on all the ROMs. No problems since!