Supergun problem....Please help.

Okay, Magnaflux and I just finished my new supergun tonight. It is using a jrok for the video, and an arcade power supply like the ones Bob Roberts sells with the eight screws in the front. I am trying to run it through a working 4 slot board.

When we first hooked it up the screen twitched consantly. Kind of like a shaking motion. It almost looks like a slow flash. I detached the 4 slot and hooked up my roommates Double Dragon and Bionic commando, both of which worked fine. We then hooked up his 4 slot out of his cab, and the twitching was back again. We took the gun and hooked it and my 4 slot up to the tv in the living room and it worked fine.

I am running a Samsung hdtv in my bedroom, and that is the tv that is skitching out. So I thought it would be a problem with the jrok and my tv, but then we tried Flux's consolized 1 slot on it and it worked beautifully. So, here I am completely lost and unable to figure out what the hell to do next. I just hope to christ some of you supergun gods will help me out. Might there be a problem with my gun and a 4 slot with my tv? If so why?

Sorry for the long post, but it is a complex problem. Please help.

TH

Try checking some of the advanced TV options to see if anything fixes it.

You may need to enter te TV's service mode(check google) to find the right option.

As much as a it's a little strange that the 4 sloters work on the other TV okay, it sounds to me like a voltage starvation issue. Can you ensure that it's got a good solid 5v at the Jamma connector. 4 slot boards suck a fair bit of juice and I know they can be pretty fussy when it comes to voltage. Some PCB's are happy to have anywhere from 4.5 to 6 volts and not play up but my 4 slot board had the exact issue you mention until I worked out that even though my power supply was outputting 5 volts at it's connectors, but had dropped the best part of a volt over the length of the power cord I made up. Cranking up the voltage with the 5 volt adjustment pot fixed it period!

Good luck with that!

We thought about that, so we turned the +5 up to 5.29. How far is it safe turn it up to? How much is usually necessary? Why would it work on my roommates TV? It just doesn't make any sense.

If you flip dip switch 1 and go to the MVS setup menu/Test grid screens, does the problem exist there also? or only while in a game?


Does the problem still occur if you disconnect the audio?

The problem persists in test mode, not just in game. Disconnect the audio from what? The RCA wires that I am using for sound weren't hooked up during testing, but the audio jacks are still hooked up to the jamma harness.

Ok, so it works fine when hooked to a different TV, but on yours it exhibits this glitching?

That's the case, but my buddies consolized 1 slot works fine, and it uses a jrok also.

On second thought, I never did check on the motherboard to see if the motherboard is getting a goof 5V. 5V is coming off the power supply to the jamma harness, but I think we should backtrack and verify that the motherboard is receiveing 5V.

right on.

Halox said:

right on.

Click to expand...

I take it by your response it had dropped a bit from the PSU to the board then? I had to turn my 4 slot PSU up to nearly 6 volts which is maxed out, but that was due to the guage of the wires in the cable I used. I wanted a nice thin cable, but it obviously hit it pretty hard as a result.

Okay, here is the update. Last night after testing the voltage and it still not working, Magna and I were about to commit simultanious ritual suicide when he had a brainstorm. We rushed to his house and picked up his consolized 1-fz and hooked it up to my supergun on my television. Eureka! It works like a dream.

Conclusion: 4 slots do not play well with Samsun widescreen HDTV's.