CPS2 A board freezing

[mRCaESaR]

Thought I'd reach out on these forums with the recent cps2 issue I seem to be having.

I've purchased a couple cps2 a and b sets (Ssf2 and xmen vs), one set is working perfectly fine, the other set seems to have an odd behaviour where it freezes no matter what b board is installed.

I've tested 4 different b boards (Progear and SSF2X conversions, xmen vs sf, and Ssf2) so far and they all exhibit the same behaviour where the game would boot, then shortly after it would just freeze. The sound still stays on, but I can't do anything else without a power cycle.

The moment I change A boards, the behaviour disappears.

I've tested two different cabinets and they both show the exact same behaviour where it would freeze, but the sound would still stay on.

I'll get some power readings later, but I wouldn't have thought that'd be the issue since my other 3 cps2 a boards work perfectly fine in the same cab.

I can hear and see the fan is working.

I haven't "opened" up the a board yet as it's completely sealed - and I don't know how to open that capcom lock thing yet.

Has anybody here experienced this issue and resolved it?

Thanks