Neo Geo Pocket Color Troubleshooting

I'm looking to troubleshoot a neo geo pocket color and hoping someone here might be able to help. I'm having the sub battery error message even after I've replaced the battery with a known good one (checked voltage with multimeter).

I've stripped the NGPC down and made sure the battery was making contact and even went as far as tracing the voltage to test points down the line from the battery.

I've been googling for data sheets or pinouts for the chips and PCB but haven't had much luck.

Anyone have data and or other things I might try?

Thanks in advance for any help.

Solved my own problem and it was pretty thick headed. The power supply I got with the unit was incorrect. Over voltage to the system was causing the issue and once I stopped using the AC adapter the sub battery message stopped appearing. Sorry about this silly thread. Maybe it will help someone else in the future at least.