BIOSes 427gn2a and 3276gn1 are not for VIP-IO2, just for VIP-IO and some other models.

You should stick to one of these:
http://cwcyrix.duckdns.org/ftp-archives/ftp.f … 86/486-vip-io2/

Im´m running my own VIP-IO2 with one of them (not sure which one).
I don´t think this board is especially picky about video cards but the jumpering must be 100% correct - otherwise it won´t boot. This also goes for the CPU core voltage.
Did you try a ISA graphics card?
Did you try a 5V CPU with the VRM module removed and 4 jumpers set instead?

the board is also picky about ram, and will not beep with no ram installed (witch is very weird). Most of the time if your FIC VIP-IO/IO2/GIO/VP2 will not post, it's because of ram it does not like, not because of the video card.

My advice for getting the board running is:
- use a better supported CPU (Intel or AMD DX2 for example) for testing
- get a hold of some more FPM ram and make sure it's fast page, as it can be hard to tell if SIMMS are FPM or EDO just by looking at them - something with Ti or SEC chips will run on these boards for sure
- get a hold of an ISA video card. Any card, just for diagnostic purposes
- since you flashed the bios, make sure you change the jumper to the right of the bios socket from 1-2 to 2-3 (1-2 -> EPROM, 2-3 -> Flash EEPROM).

Thanks for replies!

majestyk wrote on 2021-06-19, 05:18:

Did you try a ISA graphics card?

I only have the VLB ISA card at the moment, I'll order one 😀
I think the Trident can't be configured to run off the ISA bus so maybe it's VLB only.

majestyk wrote on 2021-06-19, 05:18:

Did you try a 5V CPU with the VRM module removed and 4 jumpers set instead?

Yes, I tried it today and measured the socket voltage again, it's not spot on 5.0V but around 4.9xV.

Socket3 wrote on 2021-06-19, 07:27:

- use a better supported CPU (Intel or AMD DX2 for example) for testing

Aha! I just ordered two of these, A80486DX2-80NV8T & A80486DX2-66NV8T.

Also I flashed "1164g701.zip" and nothing. Same with CMOS clear, does that need to be done while the system is offline? am I supposed to remove the battery?
I found a pin compatible RAM module from the other 486 and tried that, nothing.
"KOREA B007 9451 FFF HM514400BS7" printed on the ICs so it's FPM https://ram-co-shop.de/4-MB-FPM-RAM-non-Parit … i-HM514400BS7_1

The BIOS I tried:
http://cwcyrix.duckdns.org/ftp-archives/ftp.f … o2/1164g701.zip

VLB and ISA are completly different busses... a VLB card will not run off the ISA bus alone...

Kasreyn wrote on 2021-06-19, 11:18:

Also I flashed "1164g701.zip" and nothing. Same with CMOS clear, does that need to be done while the system is offline? am I sup […]
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Also I flashed "1164g701.zip" and nothing. Same with CMOS clear, does that need to be done while the system is offline? am I supposed to remove the battery?
I found a pin compatible RAM module from the other 486 and tried that, nothing.
"KOREA B007 9451 FFF HM514400BS7" printed on the ICs so it's FPM https://ram-co-shop.de/4-MB-FPM-RAM-non-Parit … i-HM514400BS7_1

The BIOS I tried:
http://cwcyrix.duckdns.org/ftp-archives/ftp.f … o2/1164g701.zip

In that case you probably missed a jumper. The VIP-IO and IO2 also have 4 resistor networks (long balack things with pins - RN20 and RN22 if I remember correctly, they're between the voltage regulator module and the CPU socket) that need to be correctly configured for the board to post, make sure you set them up correctly as wel

I have now re-tested this with an AMD DX2 66MHz + ISA GPU, but the issue persists, no VGA output.

POST codes are either "09 08" or "C5 C1".
It can end up at either after power cycle but usually it ends up at the former.

I removed the cache ICs + tag, sprayed some contact cleaner + toothbrush, after that the POST codes are usually "08 C5", strange!

Any ideas what else I can try to get this stubborn motherboard working?

Picture below of how I have configured the jumpers, it should be correct for AMD DX2 but there might be something I missed.

https://stason.org/TULARC/pc/motherboards/F/F … 86-VIP-IO2.html
http://opa.crabdance.com/txt/486-VIP-IO2%20Mo … nfiguration.pdf

J7 and J29 should be both open. J7 closed is cmos memory clear, if you set this the board will not power up.

Page has been updated:
https://theretroweb.com/motherboards/s/fic-486-vip-io2

The bios that was sent by email is not for this board BTW. It's for a VT82C495 series chipset, not this one. On the page 2 bioses are listed that should work with this board. There's also a complete user manual.

Thanks for the info @evasive

Sounds like this could be why it isn't working or a way to get it working again !

It spent the last decade untouched in my basement, as far as I know it's the original BIOS that I dumped, it's why I linked to it in my initial post.
I didn't have access to a programmer until recently and this was the only 486 with this type of BIOS, so it couldn't have been swapped in from a different computer.

But as you may know, memory can be a little fuzzy recalling the history of a specific computer after so many years 😀 I seem to recall it was working and one of the HDDs from it boots into Linux 2.2 I might have used it as an IRC client..
Anyway.. thanks for this.. I will be trying the BIOS from https://theretroweb.com/motherboards/s/fic-48 … p-io2#downloads