Neo Geo MVS Backup RAM error

[mathewbeall]

Hi Folks!

I have my OMVS consolized MVS that I just dropped the HDMI kit into a few weeks back - I played it for a few hours, all good.

I fire it up today - and this is what I am greeted with

BACKUP RAM ERROR
ADDRESS WRITE READ
00D00000 5555 555A

What should I fix?

Matt

 

[Rom1]

Look at broken trace between backup RAM and the CPU using a multimeter.

If traces are ok, it's most probably a bad RAM.

 

[mathewbeall]

Any idea which RAM chip it would be - since there are 2 in the backup area?

 

[ggallegos1]

What happens if you clear the backup ram?

 

[ack]

It will be the top one. Details on how you can figure out which can be found here

https://github.com/jwestfall69/neogeo-diag-bios/blob/master/docs/ram.md

 

[mathewbeall]

What happens if you clear the backup ram?

Remind me how to do this? A search didn't reveal it.

 

[ggallegos1]

Turn on the board with all the dips set to "on" and leave it running until it says backup ram cleared.

 

[mathewbeall]

Turn on the board with all the dips set to "on" and leave it running until it says backup ram cleared.

Tried that - still go the RAM error.

I have some pieces on order - so hopefully a swap out of the chip will work!

Matt

 

[ggallegos1]

Tried that - still go the RAM error.

I have some pieces on order - so hopefully a swap out of the chip will work!

Matt

Damn, good luck and keep us posted!

 

[Hansuke]

Tried that - still go the RAM error.

I have some pieces on order - so hopefully a swap out of the chip will work!

Matt

Did you ever fix this?