Beep and then hitting the floppy sounds like a bootblock BIOS recovery mode, but I didn't think that kind of thing appeared until 2 or 3 years later. We might have to dig into one of the Intel site archives (they wiped old stuff) to figure that out.

Edit: also it's got that extra power connector, it is maybe one of those halfass AT going on ATX implementations needing 3.3V.... also may be made for Dell and have the PSU pin assignments switched around to special Dell dumbass config.

Thanks for your answer!
You are right, the board was in recovery mode due to a missing jumper.
The bios must be bad because with the jumper in the correct position there is no more post beep.
I found a recovery utility that I'm trying right now.
The connector is according to the manual a 3.3volts connector for the pic slots. Do I need to have it plugged in?
I have an older enermax atx with an "aux" connector looking to be fit for it. Is that it?
Let's pray 🙏!!

Update:
The recovery seems to start but never ends . It should last between 30 to 60 seconds and I left it for 30 minutes and still nothing.
Maybe I need another power supply?

Have you tried putting a battery in it? Some mb are said to not run without one.

Joakim wrote on 2024-08-15, 17:43:

Have you tried putting a battery in it? Some mb are said to not run without one.

Yes I put a fresh cr2032 in it. I just ordered an old enermax PSU with an aux connector.
I don't get why it doesn't proceed With the recovery!

So I read the first messages, and I can tell you that the card could be working, you just have to find the hardware of the period or something older, even if you use a PCI VGA, you might not see anything on the video, because not all PCI VGAs they work in an old PC.
To put it simply, use two 72 PIN RAMs, a VGA ISA, and a Pentium 75 or at most 100 MHz CPU, check all the jumpers (download the pdf manual), and regarding the six PIN connector, do not use an ATX power supply, only AT power supplies with the third connector (should be called P10), there is no 3.3V in the MB ATs, the power supplies only have 5V and 12V (positive and negative).

PC@LIVE wrote on 2024-08-15, 20:14:

So I read the first messages, and I can tell you that the card could be working, you just have to find the hardware of the period or something older, even if you use a PCI VGA, you might not see anything on the video, because not all PCI VGAs they work in an old PC.
To put it simply, use two 72 PIN RAMs, a VGA ISA, and a Pentium 75 or at most 100 MHz CPU, check all the jumpers (download the pdf manual), and regarding the six PIN connector, do not use an ATX power supply, only AT power supplies with the third connector (should be called P10), there is no 3.3V in the MB ATs, the power supplies only have 5V and 12V (positive and negative).

Well I tried with a S3 vision 864, that's the oldest one I have right now. I don't have any Isa card available.
The thing is that it's not even posting with the jumper back to normal bios opération.
The mb is setup according the manual, the ram too.
This is really puzzling! I have another S5 working just fine and also a 486dx4 mb PCI working too with the same configuration.
This one is such a headache, but hey that's all the fun with retro gear.

Here are some pictures of the PSU I found. Would be suitable for this mb with atx to at adapter?
I will try to find an at Psu with P10 connector though.

It's fixed!
Thanks a lot to Bit Wrangler for pointing out the bootblock recovery sequence.

Here is how I did it, maybe it will help someone later on.
The original recovery disk (look for zapped.exe online) didn't work for me I don't know why so I used the mr.bios method:
-download the mr bios file from The Retro Web
-Extract the content of the MR.BIOS archive and rename MR_ZAPPA.BIO into ZAPPA.BAK
-copy AUTOEXEC.BAT, ZAPPA.BAK and MR_ZAPPA.EXE to the floppy
-put jumpers jl1 into recovery mode (form 1-2 to 2-3)
-start the computer, once the floppy disk light shuts off it's done!
-shut off, put the jumper to 1-2 again and your good to go with a new bios!

Now time to figure out why cachechk seems to detect only one cache!

hebergeur en ligne

Tyrhus wrote on 2024-08-15, 20:56:

Well I tried with a S3 vision 864, that's the oldest one I have right now. I don't have any Isa card available. The thing is tha […]
Show full quote

PC@LIVE wrote on 2024-08-15, 20:14:

So I read the first messages, and I can tell you that the card could be working, you just have to find the hardware of the period or something older, even if you use a PCI VGA, you might not see anything on the video, because not all PCI VGAs they work in an old PC.
To put it simply, use two 72 PIN RAMs, a VGA ISA, and a Pentium 75 or at most 100 MHz CPU, check all the jumpers (download the pdf manual), and regarding the six PIN connector, do not use an ATX power supply, only AT power supplies with the third connector (should be called P10), there is no 3.3V in the MB ATs, the power supplies only have 5V and 12V (positive and negative).

Well I tried with a S3 vision 864, that's the oldest one I have right now. I don't have any Isa card available.
The thing is that it's not even posting with the jumper back to normal bios opération.
The mb is setup according the manual, the ram too.
This is really puzzling! I have another S5 working just fine and also a 486dx4 mb PCI working too with the same configuration.
This one is such a headache, but hey that's all the fun with retro gear.

Here are some pictures of the PSU I found. Would be suitable for this mb with atx to at adapter?
I will try to find an at Psu with P10 connector though.

Regarding the power supply, the one in the photo is for a P4 PC, I advise you against connecting that six-pin connector into socket 5.
Surely there will be differences, and you could damage the board, that connector was present in the AT power supplies of the early 90s, it was later eliminated, I don't think there are ATX-AT adapters with three AT connectors (instead of two).
I saw that you managed to make the card work, if this is indeed the case, congratulations.

PC@LIVE wrote on 2024-08-16, 11:22:

Regarding the power supply, the one in the photo is for a P4 PC, I advise you against connecting that six-pin connector into soc […]
Show full quote

Tyrhus wrote on 2024-08-15, 20:56:

Well I tried with a S3 vision 864, that's the oldest one I have right now. I don't have any Isa card available. The thing is tha […]
Show full quote

PC@LIVE wrote on 2024-08-15, 20:14:

So I read the first messages, and I can tell you that the card could be working, you just have to find the hardware of the period or something older, even if you use a PCI VGA, you might not see anything on the video, because not all PCI VGAs they work in an old PC.
To put it simply, use two 72 PIN RAMs, a VGA ISA, and a Pentium 75 or at most 100 MHz CPU, check all the jumpers (download the pdf manual), and regarding the six PIN connector, do not use an ATX power supply, only AT power supplies with the third connector (should be called P10), there is no 3.3V in the MB ATs, the power supplies only have 5V and 12V (positive and negative).

Well I tried with a S3 vision 864, that's the oldest one I have right now. I don't have any Isa card available.
The thing is that it's not even posting with the jumper back to normal bios opération.
The mb is setup according the manual, the ram too.
This is really puzzling! I have another S5 working just fine and also a 486dx4 mb PCI working too with the same configuration.
This one is such a headache, but hey that's all the fun with retro gear.

Here are some pictures of the PSU I found. Would be suitable for this mb with atx to at adapter?
I will try to find an at Psu with P10 connector though.

Regarding the power supply, the one in the photo is for a P4 PC, I advise you against connecting that six-pin connector into socket 5.
Surely there will be differences, and you could damage the board, that connector was present in the AT power supplies of the early 90s, it was later eliminated, I don't think there are ATX-AT adapters with three AT connectors (instead of two).
I saw that you managed to make the card work, if this is indeed the case, congratulations.

Okey i won't use it then.
Yes indeed I successfully installed a MR bios bios for this MB.
I tried a lot of other bios, but it never posted with Intel, gateway or vobis bios.

The problem i now have is that the bios doesn't recognize L2 cache.
I made another post about that.