Stupid question on switching PSUs

[KalessinDB]

My X-Men is having some issues that seem maybe ground related. We're poking around with a multimeter, and the jamma harness doesn't seem to be getting ground. The PSU doesn't seem to be putting it out on the DC wiring.

Should I still have a ground on the DC pins when it's powered off?

I'm willing to replace the PSU if I need to, but would rather not.

 

[streetfighterken]

If there is "no ground" the game will not power on at all. If you've checked that you're getting 5v and it's still acting up, the psu needs to be replaced.

 

[KalessinDB]

Basically, continuity on ground wasn't working when we poked at it (while off) vs the grounding strip. We weren't sure if it was supposed to be when it was off or not.

But now we've powered the PSU on when not connected to my machine and looked at pins and realized ground is fine - but 12v is low. If 5v is right, 12v is showing 10.4 and if we dial it up to 12v the 5v is showing 5.7.

So I'm thinking the PSU is the issue. Going to have to weigh the cost between having my local arcade tech fix it and just buying a new PSU.

 

[streetfighterken]

12v is only for sound as far as I know. 10.4v should be fine. Keep in mind readings are not accurate when the psu is not loaded (powering a pcb). A new switching psu is only ~$25.

 

[KalessinDB]

The sound is what's having the most issues and what started this whole nonsense. It was crackling, so I got Mitsurugi to install a new audio chip. When I got it back, it was loud and buzzing and would reset - but if I unplugged the sound header I could play just fine. And plugging the board into another cabinet plays just fine.

Now (since getting the second monitor repaired) it's acting up even worse, which has made us start looking for possible ground faults or - as we're now suspecting - a bad PSU.