Your board is also known as the Chaintech 9VIF. Sorta like MSI giving names an alter ms-# 🤣 but you already figured that I think. Yeah both are at Driver guide, only one thru the .tw archive....
Looking thru the archives, there are slightly newer (by only a few months) for rev C & E and a diff one for rev D, F and G. If I had to guess you have a rev D (as in d31 since there is no rev A as in vA3).
Here is the archive page: http://web.archive.org/web/20050309071039/htt … CSNo=4&PISNo=28
Since your bios is socketed you could flash it and if if wrong try the bootblack flash method. If that does not work then find someone with an eeprom programmer.
I seriously suggest you save the current bios and post it here (zipped) before trying to flash it. Some of us might be able to tell from it's code if it is rev d by comparing to the others.....
There is no FAQ page found (yet) that helps figure out if that d31 does mean a rev d.
Attached the bios and manual in case anyone wants a quick look w/o searching. Also here is something interesting: the hex diff between the C&E versus D,F&G is shown in the picture, not much change between them....

Thanks, I read your reply late, but I just went and flashed with bios filename "ES675M-9.bin", can't remember what download it was but at least at one point I also thought it might be D revision because of the text printed.

All went fine and seems like everything is working, just tested with Ubuntu, USB ports, sound, integrated graphics, AGP slot etc all work.

Apparently there are versions of this board where ISA slot is soldered in place, what revision that would be I don't know but maybe some bioses have stuff specific for those boards.

I noticed that there is model sticker on PCI slot, it didn't help much when googling.

ES-675M-000AG

Good to know ! Odd the sticker says v3.0 10/15/2002 which is the newest bios, also the 9A5F is the newest bios checksum....
Am wondering if someone down flashed the bios at some point......and sorry i included wrong manual in my .zip..