So I've been putting this off for ages and figure it's about time to get this fixed.
Bought a NeoSD MVS right around launch and it hasn't worked since day one. I reached out for support and got an updated firmware at the time but that didn't fix the issue and I just never got back around to addressing it as I had bigger fish to fry at the time.
Anyway, I have the correct rom set, my 5v line is fine. I've tried three different cabinets, three different MVS mobos (two 1Fs and one 1FZ).... all of which play the rest of my carts without issue.
Games will load up without issue but then constantly reset or the Unibios will throw an error within 90 seconds to 5 minutes of being on. Tried several different games but larger games tend to do it more quickly. People have recommended cranking the voltage a little bit on the 5v line to see if it's just a lack of power but I generally avoid mucking with 20+ year old PSUs unless the voltages are off.
I'm happy to provide pictures, video, serial numbers, whatever is needed.