Help! CPS2 arcade machine won't power up all the way


I was switching out my CPS2 A boards (Marvel Super Heroes for ST) and after the switch there is no longer a picture (no matter the board installed) and the B board fan doesn’t come on. The ST board is phoenixed so its shouldn’t be a double suicide battery problem. Also I was playing Marvel Super Heroes earlier in the day.

Is it possible that my B board has gone bad? The fan used to come on even when the A board wasn’t set properly (which happened from time to time).

The screen still receives power (the screen shows a distorted, off center static), and all the lights come on (marquee etc). I don’t think it would be a power supply issue…

I can get pics of the screen while on if need be. I did a wire trace back to the power supply and screen, but I didn’t see any obvious issues.

It is pretty dirty in there. Maybe the dirt is an issue?

I change my A board only once every couple of months.

I don’t know what I’m gonna do without my machine. I use it pretty much every day :sad: I can’t really afford to buy any parts right now (especially with mvc3 on its way), but if I have to I will eat ramen…

Any other info that would be helpful for a diagnosis let me know! I’m probably going to try to do some more hardcore wire tracing and cleaning tomorrow.


The B board is the likely culprit here. If I were you I’d open up the B-board case and clean it with compressed air and alchohol on any grimey spots. Make sure the risers are in place as they can come loose… I had one B board where they’d all fallen out of place and I had to superglue them in the correct position. If I remember correctly I believe it does require a security torx bit so hopefully you have a set of those.


Screen and marquee flourescent lights aren’t powered by the power supply; they are connected to the AC. Power supply is the very first thing you should check, especially the fuse. Unless the fuse is obviously, visibly blown, time to whip out the multimeter and make there is the expected +5 and +12 volts available on the Jamma harness (with nothing plugged into the harness).

Don’t crack open the CPS2 boards yet.


Thanks for the quick replies!

I just noticed that the power supply fan is not coming on either. I’m guessing this means its the power supply? I hope? I don’t think I can get to the fuse without a screwdriver. Plus the whole power supply is looking pretty rusty (I’m not the original owner and the last guy didn’t take very good care of the machine).

My multimeter is at my parents place along with all my other tools… I’m going to go over and pick up everything to do the work this weekend.

I’m kind of a n00b: What does the H dial thing on the power supply do?

I will check the power supply output (I removed it from the machine completely) and then check the fuse (if its replaceable). I think I can afford another power supply (they look to be $30) easier than another B board (I only see them at $70 or so).

If it comes to buying another power supply, do you have any recommendations on which one I should buy and from where?