It seems you have a 486 DX/2 CPU clocked at 66 MHz (FSB 33).
Which CPU do you have (please take a photograph).

For your floppy problem: What ISA clock do you have? Is it something like CLK/4 or 7.14 MHz?
Do problems change when you disable L1 and/or L2 cache?

Well, the board looks like it has 256KB cache. The cachechk program only shows 128KB.

My bet is this:
PC-Chips modified BIOS that will always show 256KB L2 cache. Cache chips may or may not be remarked but are real cache chips as cachechk shows L2 cache and speeds indicitave of real L2 cache.

The soldered cache config jumpers must be set at 128KB which makes me think that the L2 cache chips are remarked. Otherwise why would PC-Chips need to fake the cache size to 256KB and solder the jumpers to 128KB?

OR... since the second row of cache chips doesn't have the same exact markings, it may be that somebody added those to bring it up to 256k and also have it run "dual-rank" but didn't know that they needed to desolder and reconfigure the cache jumpers.

For that matter, maybe it originally had fake cache and somebody replaced all the cache chips with real ones. It is odd to see 20ns chips on that board. I would expect 15ns to be normal.

I have exactly the same motherboard and the cache chips are perfectly legit. The problem is that the chips are soldered in and your motherboard detects 128K only with cachechk, while it should detect 256K, as the chips are 32K. Perhaps one (?) of them is faulty. I'd get the chips out, get new, tested to be good ones and put in them in sockets.
The problem with keyboard sounds like a bios problem. The bios on these motherboards is also soldered in and it is crappy. I'd get it out and socket it. Find a thread with discussion of this motherboard here on Vogons and try some bioses from there. You will have to program the bios using EPROM programmer (Need to UV-erase first).

Do these PC-Chips boards run correctly with just one single DRAM slot populated?

Thank you all for the tips.

The cpu is obviously a dx2 66, jumpers are ok I suppose.
Unlucky everything in this motherboard is soldered and I'm not comfortable to try desolder stuff. I can confirm that the bios chip is indeed and eeprom or at least not an eprom since it doesn't have the window for using the uv light.

The bios problem I suppose it is an issue with that creepy ami bios that look like windows.

I have the very same issues with a mb-1433/50uiv-a rev 3.1 this one has socketed thing so maybe it will be easier to spot the issues.

In the meanwhile the sd card is gone, now it gives issues even after being formatted, I tried to connect an hard drive but the controller keep saying i\o error.

majestyk wrote on 2021-12-29, 18:56:

Do these PC-Chips boards run correctly with just one single DRAM slot populated?

I tried with 1 and 2 slot populated, but since the 128kb cache, 32mb of ram give error with cachechk

Now I have another problem, the other umc motherboard when I enter the bios it keeps showing the hourglass wait screen and doesn't go forward, the bios is socketed but I can't find the right model, it's a Biostar moterboard mb1433, what can I do?

Get a spare motherboard tray for testing. Because of the large distance between the back of the ISA and the VLB at the front a lot of flex can happen when you're seating cards, and you effectively end up popping one card out while you're trying to put another one in. It's not just that either, because the VLB slots are so stiff, you might also be applying enough force/twist to pop out SIMMs a little or disturb the CPU... they really, really, really, like to be fastened down securely.

Nemo1985 wrote on 2021-12-29, 17:22:

PC Chips M912 rev 1.4 (I still didn't understand if it is with fake cache or not).

I had a similarly configured PC Chips motherboard. Bank 0 contains real (at least functional) SRAM ICs, bank 1 is filled with empty DIP28 shells, but they are made from high quality epoxy.

BitWrangler wrote on 2021-12-30, 23:35:

Get a spare motherboard tray for testing. Because of the large distance between the back of the ISA and the VLB at the front a lot of flex can happen when you're seating cards, and you effectively end up popping one card out while you're trying to put another one in. It's not just that either, because the VLB slots are so stiff, you might also be applying enough force/twist to pop out SIMMs a little or disturb the CPU... they really, really, really, like to be fastened down securely.

When I'm testing the motherboard I ended up using an isa video card and isa controller :\

So I did some further tests. I tried with every vlb card I have (and the isa one), an hard drive of 2gb, it always get formatted as 503mb (despite the dimension in the bios is showed correctly).
Why is that?
I used superfdisk and windows 98 fdisk, without any change

I would hook it up to a newer computer, get the drive parameters off of that and then enter them manually on this motherboard.

Nemo1985 wrote on 2022-01-01, 01:31:

So I did some further tests. I tried with every vlb card I have (and the isa one), an hard drive of 2gb, it always get formatted as 503mb (despite the dimension in the bios is showed correctly).
Why is that?
I used superfdisk and windows 98 fdisk, without any change

BIOS has a limit of 504MB. Try making a single partition of less than that size. That should fix the corruption when moving between old and new. The rest of the drive will be waste space; unusable. Unless you get a XT-IDE bios in there to take over drive size translations. You could also use drive overlay software to use the whole capacity but you cannot swap between old and new computers then.

moz2186 wrote on 2022-01-01, 04:39:

Nemo1985 wrote on 2022-01-01, 01:31:

So I did some further tests. I tried with every vlb card I have (and the isa one), an hard drive of 2gb, it always get formatted as 503mb (despite the dimension in the bios is showed correctly).
Why is that?
I used superfdisk and windows 98 fdisk, without any change

BIOS has a limit of 504MB. Try making a single partition of less than that size. That should fix the corruption when moving between old and new. The rest of the drive will be waste space; unusable. Unless you get a XT-IDE bios in there to take over drive size translations. You could also use drive overlay software to use the whole capacity but you cannot swap between old and new computers then.

I see, why the bios then shows the real dimension of the hard drive? Updating the bios could help the issue?

Nemo1985 wrote on 2022-01-01, 16:19:

I see, why the bios then shows the real dimension of the hard drive? Updating the bios could help the issue?

When you configure the hard drive the size is calculated based on the parameters (Cylinders, Heads and Sectors per track) so it will show up fine. But the BIOS calls that perform actual operations on the hard drive cannot handle more than 504MB due to combined limitations of the BIOS and the IDE specs:

http://web.inter.nl.net/hcc/J.Steunebrink/bioslim.htm#504MB

If there is a newer BIOS for that board with LBA support, that would do the trick, otherwise you can try drive overlays or something like XT-IDE.

Or some other controller with a BIOS on it that supports a larger size.

Thank you very much for those precious information.

I noticed that noone of the vlb controller cards have a bios of their own (nor does the ISA goldstar prime 2).
Since I have some isa network cards, i'm going to try the xt-ide solution, I will post about the result later.
I also changed motherboard with a ASUS VL/I-486SV2G, which solved any problem about the floppy drive not detected\working. I noticed that there is a 1999 beta bios, but the card use an old eprom and the eeprom I tried are not readed properly.
Can you advice me a proper eeprom? The bios size is 64kb.

Nemo1985 wrote on 2022-01-01, 18:50:

Thank you very much for those precious information. […]
Show full quote

Thank you very much for those precious information.

I noticed that noone of the vlb controller cards have a bios of their own (nor does the ISA goldstar prime 2).
Since I have some isa network cards, i'm going to try the xt-ide solution, I will post about the result later.
I also changed motherboard with a ASUS VL/I-486SV2G, which solved any problem about the floppy drive not detected\working. I noticed that there is a 1999 beta bios, but the card use an old eprom and the eeprom I tried are not readed properly.
Can you advice me a proper eeprom? The bios size is 64kb.

What is the brand and other writing on the EPROM? Might be hidden by a sticker or on the bottom.

cyclone3d wrote on 2022-01-01, 19:28:

Nemo1985 wrote on 2022-01-01, 18:50:

Thank you very much for those precious information. […]
Show full quote

Thank you very much for those precious information.

I noticed that noone of the vlb controller cards have a bios of their own (nor does the ISA goldstar prime 2).
Since I have some isa network cards, i'm going to try the xt-ide solution, I will post about the result later.
I also changed motherboard with a ASUS VL/I-486SV2G, which solved any problem about the floppy drive not detected\working. I noticed that there is a 1999 beta bios, but the card use an old eprom and the eeprom I tried are not readed properly.
Can you advice me a proper eeprom? The bios size is 64kb.

What is the brand and other writing on the EPROM? Might be hidden by a sticker or on the bottom.

I don't know actually, I tend to not peel off the stickers since it destroy them. Do you know how to peel it off and being able to put it back? Maybe with some hot air while peeling?

In the meanwhile the xt-ide with network card failed, I just have 2 isa network cards:
mym2e8e3100 but jumpers are not populated.
The other is this card:

it originally had the jumper on soft configuration setting, I tried the first and the second position but the xt bios is not showed during the post.

I swear I never had so many issues neither with 386 board

Nemo1985 wrote on 2022-01-01, 20:26:

I don't know actually, I tend to not peel off the stickers since it destroy them. Do you know how to peel it off and being able […]
Show full quote

cyclone3d wrote on 2022-01-01, 19:28:

Nemo1985 wrote on 2022-01-01, 18:50:

Thank you very much for those precious information. […]
Show full quote

Thank you very much for those precious information.

I noticed that noone of the vlb controller cards have a bios of their own (nor does the ISA goldstar prime 2).
Since I have some isa network cards, i'm going to try the xt-ide solution, I will post about the result later.
I also changed motherboard with a ASUS VL/I-486SV2G, which solved any problem about the floppy drive not detected\working. I noticed that there is a 1999 beta bios, but the card use an old eprom and the eeprom I tried are not readed properly.
Can you advice me a proper eeprom? The bios size is 64kb.

What is the brand and other writing on the EPROM? Might be hidden by a sticker or on the bottom.

I don't know actually, I tend to not peel off the stickers since it destroy them. Do you know how to peel it off and being able to put it back? Maybe with some hot air while peeling?

In the meanwhile the xt-ide with network card failed, I just have 2 isa network cards:
mym2e8e3100 but jumpers are not populated.
The other is this card:
photo_2022-01-01_21-24-55.jpg
it originally had the jumper on soft configuration setting, I tried the first and the second position but the xt bios is not showed during the post.

I swear I never had so many issues neither with 386 board

The sticker can be removed safely, takes UV lamp to erase (or sitting in the sun a long time), then can be covered back up with tape or another sticker. Black electrical tape would work.

Good luck with the XT-IDE bios, I haven't been able to get it working myself outside of buying a prebuilt card with the CF slot. However, the bios needs to be configured to the address that whatever card is expecting a rom to be (ex D000) AND the bios needs to be enabled in the card setup if there are no jumpers to enable it (for example a PNP ISA NIC)