Backup Ram Error: Unwritable

Misos

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Joined
Aug 17, 2018
Posts
57
I have a Mv1c with a backup ram error, whem I use the Unibios I can bypass the error but I can't use it in MVS mode.

Using the Neo Diagnostic Bios, i got a screen telling me that the upper Bram Is Unwritable.

Should I replace the backup ram? I assume it's the upper Winbound chip (RAM2), right?
 
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shadowkn55

Genbu's Turtle Keeper
15 Year Member
Joined
Dec 9, 2006
Posts
2,386
Try replacing the 74HC32 nearby. Makes sure none of the traces around have corroded. The write signals for backup ram pass through this chip.
 

Misos

New Challenger
Joined
Aug 17, 2018
Posts
57
Just an Update for anyone with the same problem.
I Replaced the 74HC32. Same thing.
Replaced the Ram2, same thing.
Then replaced Ram 4, and all tests passed.
So the upper ram must be the one closest to jamma connector.
 
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