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MV1FZ boots into garbled error

ptom98

ptom98

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So my MV1FV started throwing an error on boot, unfortunately all garbled and wouldn't let me proceed.
So I swapped out the original BIOS for a UNIBIOS4 and also tried with the NeoDiag, have attached images of the results.

With the UNIBIOS on boot I get an error, if I go onto the Setting Menu it displays but again text is garbled.
I'm able to bypass the error, in MVS mode the game boots, looks fine but has no sound and when a credit is inserted it crashes, in AES mode game starts and works without issue, also the UNIBIOS menu isn't garbled and reads fine.

Looking at the error messages it king of looks like it's complaining about the Backup RAM, but just wanted to check if anyone had any ideas/can confirm the issue as I don't have much experience in resolving.
 

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No, original battery is still in, I've got a 3202 battery holder which I was planning on installing at some point to replace it.
 
Looks like the error reads backup ram, combined with that AES mode wouldn't use the backup ram for read/write it would make sense that this is at least one of the issues. Start debugging that backup-ram section :)

So the value on all screens seems to point to upper backup ram since the value is different on write/read on the first part of the presented value.
Check traces and then consider changing the memory chip if nothing obvious jumps out of the continuity tests!
 
Last edited:
ptom98 said:
No, original battery is still in, I've got a 3202 battery holder which I was planning on installing at some point to replace it.
Click to expand...
You probably should've at least clipped that off by now. I would remove it now and check for damage to the board around the battery.
 
Neo-Alec said:
You probably should've at least clipped that off by now. I would remove it now and check for damage to the board around the battery.
Click to expand...
have removed it this evening, doesn't look it's leaked or caused any damage. got a replaceable battery holder in place now.
will look at testing the backup ram over the weekend
 
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