MV1C backup ram error

When turning the board on (without a game plugged in), the monitor displays:

BACKUP RAM ERROR

ADDRESS
00D00000

WRITE
0000

READ
0100

I initially got the error with metal slug and it had different codes than above:

ADDRESS
00D00008

WRITE
0008

READ
0108

Does this all come from possibly a bad backup battery? Te board otherwise looks fine to me, but I took pictures of it (minus the shell) if that would help matters.

Little help?

Flip all the hard dips on and if it says Work RAM test it means it's passing tests. Run it for 10 minutes, if any errors it will show.

Flipped all the DIPs and "work ram test" never appeared. Just displayed the backup ram error info.

...and now my MV1FS is coming up with a Z80 error when trying to turn on. Fitting that both my boards crap out right when I order a NeoSD cart. Sigh.