Until someone finds the AMI BIOS for this board (and hopefully a POST string is found), you could give the BIOS images from a Fox M board a try (same chipset).
http://www.win3x.org/uh19/motherboard/show/5180

I don't think the "Ami" keyboard controller is a problem. They all work the same.

You should try the Supersoft landmark test ROMs in your computer http://www.minuszerodegrees.net/supersoft_lan … dmark%20ROM.htm to see if your board has still some life

computerguy08 wrote on 2021-03-22, 13:34:

(and hopefully a POST string is found)

Yes, the fact that the manufacturer could be identified with a working AMI BIOS is very frustrating. 😒 I have tried to comb through the one part of the BIOS I managed to dump and noticed that it is actually possible to identify some parts of it. E.g. it is clear that the copyright strings are in there by just filling in the blanks. E.g. "()Aeia earns" --> "(c) American Megatrends". Etc. So potentially half of the ID string is in there, isn't it? Maybe someone with more luck than me can find it. Maybe the number of possible manufacturers could then be narrowed down.

computerguy08 wrote on 2021-03-22, 13:34:

you could give the BIOS images from a Fox M board a try (same chipset).
http://www.win3x.org/uh19/motherboard/show/5180

I flashed one of those two BIOS that are available but unfortunately no luck. I don't know if it is important. But the original EPROMS are NM27C256 and I do only have W27E512. Which I just fill up by putting in the 32k images twice. This has been working many times before but I just wanted to mention it.

Deksor wrote on 2021-03-22, 13:35:

I don't think the "Ami" keyboard controller is a problem. They all work the same.

Ah! I've read conflicting things on that one. Some wrote "it cannot possibly work". So I thought they had to match.

Deksor wrote on 2021-03-22, 13:35:

You should try the Supersoft landmark test ROMs in your computer http://www.minuszerodegrees.net/supersoft_lan … dmark%20ROM.htm to see if your board has still some life

Stupid question: Which one? I tried the one for the IBM 5170 (because highest number is best, right? 😉) but unfortunately also no luck. I've waited more than 20s on each try. I only have VGA cards unfortunately and I don't know if they are "self initializing". But if I understood correctly that should at least give me an error beep sequence if it is working at all.

IBM 5170 is the right one. It's the AT. Others are for pre-at machines.

It won't work on a VGA card as far as I know, but yeah I think it should give you some beep codes (finishing all the tests take more than 20 seconds though)

Not sure if it it helps but the power and turbo LED are working. Turbo LED also responds to the turbo switch being toggled. I'm guessing this is very low-level functionality but wanted to mention it.