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GA-586VX - CMOS settings don't save (besides date / time)

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First post, by kevmif

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Really odd one here. No matter what I do, this GA-586VX board will not save any BIOS changes besides date and time.
This means, I am stuck with Primary HDD on AUTO and cannot configure any other HDD / FDD options, nor can I change any other settings (memory timings etc).

I did successfully flash it to the latest BIOS as per the Gigabyte website (good on them for still hosting such old stuff).
There is no clear CMOS option, so I pulled the RTC chip overnight. When I put it back in this morning, the time had reset, but the issue persisted.

This is the board: https://theretroweb.com/motherboards/s/gigabyte-ga-586vx except mine is rev 3.37.

I tried replacing the M48T86PC1 RTC with a Dallas DS12887+ but I doubt that was the problem as the date / time was holding.

To clarify, the changes don't save AT ALL as opposed to simply not persisting after a power off. Hit Save Changes and Exit, system reboots, changes gone.

Do I have a bad CMOS chip?
Should I try downgrading to an older version? Perhaps flash again using newer version of AWARD FLASH?

So strange that date / time saves but nothing else does. Any suggestions are welcome 😀

Thanks

Reply 1 of 5, by BitWrangler

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The NVRAM for the settings is actually inside the dallas module, so if internal things are saving and external things aren't then there's a problem somwhere between it's internals and the chipset. First thing I would try is a really good clean of it's pins and socket with contact cleaner.

Unicorn herding operations are proceeding, but all the totes of hens teeth and barrels of rocking horse poop give them plenty of hiding spots.

Reply 3 of 5, by Horun

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edit :The M48T86PC has 114 bytes ram so You want a DS12887 if the board has no jumper to reset cmos (did not see one in the manual), you want a DS12887A if it does. The + just mean no-lead compliant.....
BTW those are not "century byte" fixed so you may have year issues after 2000..... the fixed ones is DS12C887 but if your board need all 114bytes versus the 113bytes of the 12c887
Pictures of same board at BadCaps show with a 12c887...

Last edited by Horun on 2024-01-10, 04:20. Edited 1 time in total.

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Reply 4 of 5, by kevmif

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Thanks Horun. There is no jumper to reset the CMOS. So the DS12887+ is the correct RTC chip for this board?
I wonder why it still won't save anything...hmm.

I got these DS12887+ chips from China a while ago and they seemed to work fine in other machines. Should I buy some DS12887A chips and try those?

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