I have a MV1B that had backup ram errors.

Replaced the backup ram, and battery and the thing is working fine.

EXCEPT...

The DIP switches don't seem to work. I cant enter test mode, and dip-7 (free play) is set to ON, even if I turn it off.

I checked with a multimeter - switching them does change the resistance between the two points on the underside of the board, so I don't think the switches themselves are faulty - it seems like something else.

Any suggestions?