Bally S9000 MBR fail after swapping MPU

[Elbandingo]

General description of problem: MBR error after swapping MPu that had bad nvram

I originally had an issue with nvram battery being low. Swapped, cleared, all was fine. Couple months pass, and sure enough battery dies again. New batteries, doesn’t clear giving error that nvram clear failed. After searching through many forums, the consensus was to replace MPU. Sourced an MPU on eBay all it was missing was BIOS and JUR chip. When it arrived, I swapped the bios and jurisdiction from old bad board to new one. Booted it up with clear card in it. Gets error after doing a memory check that MBR is failing.

I am lost as to why. When I moved the chips back to the old machine, it lets me boot to clear screen but I still get an nvram clear error. I believe I am missing some important information that might be related to the specific MpU replacement I bought even tho the board is identical. See specs below


Old board: PCA39456-0-0 rev D 428330-0738
Bios: AVBPROD807-00
317 OS
312 clear


New board: PCA39456-0-0 rev E 428330-5006


When I put the bios chip in, it is recognized on boot, and even matches previous display when I’d boot the bad board.

[Elbandingo]

To add to this, I do understand there is a matrix out there that shows what OS and clear is needed based on the BIOS, but given that I’m keeping the same BiOS, I would think my OS and clear are ok

[rickhunter]

You may have a bad cf reader on the new mpu, have you tried using the other slot for the clear card.  If it works on the other slot, it means there's probably a missing or bent pin inside the cf card reader of the slot that failed.

[Elbandingo]

Hello,

Sincere apologies. This was kind of forgotten about as in fixing this machine for my father and other priorities in life took over and I forgot I even made this post.  Well now that I have time again, I tried it again today with this MPU and the same MBR error came up. I tried both slots for the clear card and had no luck. I lack any skill or tools to be able to check any voltages etc..

I understand MBR means master boot record? Wondering how this error is related to any hardware issues as the machine was a tested unit prior to buying it.

Thank you all for your feedback, I was able to resurrect an old MPU and get my dad's white gold machine up and running today. It has a bad battery terminal I guess since every 2 or 3 reboots I get the low battery on nvram 2.

[Elbandingo]

Screenshot of error

[Elbandingo]

update:

ive scoured the forums here and found an old post that states it might be an issue with the last time it was operated, it used a different OS potentially with a different BIOS. When we received this MPU, all we did was put the BIOS and JUR chip on expecting it to work, and that may have corrupted the MBR. In the forum archive i saw a suggestion to apply the appropriate OS that was on that machine before the chips got pulled...Wondering if its worth buying a new BIOS chip off ebay that supports another OS i have..any thoughts?

[rickhunter]

You can't destroy the MBR on a cf card by using the wrong bios.  The worst that can happen is that you will get an error.  What OS and Bios combination are you trying to use now.  Also if you inserted the cf card into a windows 8 or later machine, you will corrupt the card.

[Elbandingo]

Bios: AVBPROD807-00
317 OS
312 clear
New board: PCA39456-0-0 rev E 428330-5006

i looked at the matrix linked here and it appears as if my config is ok

https://www.scribd.com/document/725330483/Bally-MPU-Compatibility-Matrix-v17

[Elbandingo]

to add to my above feedback, i just put the BIOS back in the old MPU with the same game/OS/clear cards and everything is fine. all im doing is moving the chips and CF cards over, but the MPU board is almost identical (revision difference only)

[rickhunter]

have a look at the pins inside the CF card slot.  You may have pins that are bent or damaged and thus not reading the cf card properly.