Check the true running speed with some sys info tool. Like chkcpu, NSSI, Aida32...

Alright I will try that. I also tried changing the bus speed and now the pc won't boot at all, I've set the bus speed to the defaults again yet it still won't boot. Any idea how to fix that?

Sorry if that's a dumb question, I'm pretty new to retro tech. 🙃

Failure to run at higher FSB or failure to run at all may be a sign of aging capacitors on the motherboard.
Does the motherboard work properly with other processors?

Florian J wrote on 2023-07-26, 14:06:

Alright I will try that. I also tried changing the bus speed and now the pc won't boot at all, I've set the bus speed to the defaults again yet it still won't boot. Any idea how to fix that?

Sorry if that's a dumb question, I'm pretty new to retro tech. 🙃

More details would help us help you. What is the history of this build? Was it working prior to your trying a K6-2+ CPU in it? If yes, you should try the original CPU again. It seems the BIOS you have doesn't recognize the K6-2+ CPU, which is why it cannot report the actual speed. That same thing can also cause issues with being able to POST - you may have gotten lucky a couple of times. So I recommend going back to the last known working configuration.

Do you have the latest BIOS? Assuming The Retro Web has the most current BIOS (they usually do) have a look. https://theretroweb.com/motherboards/s/tekram … 4-m-2#downloads

Jan Steunebrink has a patched BIOS for that motherboard here: http://www.steunebrink.info/k6plus.htm

gerwin wrote on 2023-07-26, 15:00:

Failure to run at higher FSB or failure to run at all may be a sign of aging capacitors on the motherboard.
Does the motherboard work properly with other processors?

Yes I've tried running it with a Intel Pentium MMX before and it ran fine. I also used to have a amd k6-2 in it before and that also worked without any issues.

Florian J wrote on 2023-07-26, 16:32:

gerwin wrote on 2023-07-26, 15:00:

Failure to run at higher FSB or failure to run at all may be a sign of aging capacitors on the motherboard.
Does the motherboard work properly with other processors?

Yes I've tried running it with a Intel Pentium MMX before and it ran fine. I also used to have a amd k6-2 in it before and that also worked without any issues.

You can test 100MHz FSB with both these processors, for that configure the multiplier to a low setting like 2x.

Repo Man11 wrote on 2023-07-26, 15:05:

More details would help us help you. What is the history of this build? Was it working prior to your trying a K6-2+ CPU in it? I […]
Show full quote

Florian J wrote on 2023-07-26, 14:06:

Alright I will try that. I also tried changing the bus speed and now the pc won't boot at all, I've set the bus speed to the defaults again yet it still won't boot. Any idea how to fix that?

Sorry if that's a dumb question, I'm pretty new to retro tech. 🙃

More details would help us help you. What is the history of this build? Was it working prior to your trying a K6-2+ CPU in it? If yes, you should try the original CPU again. It seems the BIOS you have doesn't recognize the K6-2+ CPU, which is why it cannot report the actual speed. That same thing can also cause issues with being able to POST - you may have gotten lucky a couple of times. So I recommend going back to the last known working configuration.

Do you have the latest BIOS? Assuming The Retro Web has the most current BIOS (they usually do) have a look. https://theretroweb.com/motherboards/s/tekram … 4-m-2#downloads

Jan Steunebrink has a patched BIOS for that motherboard here: http://www.steunebrink.info/k6plus.htm

The pc used to run fine with a AMD k6-2. But I accidentally broke one of the pins while taking it out.

As for the bios version I believe it's 1.03

Also here are the pc specs if that helps.

512mb of ram (2×256mb sticks)
SH-250ATX 250 Watt power supply
10GB Western digital hard drive
P5M4-M+ motherboard

gerwin wrote on 2023-07-26, 16:40:

Florian J wrote on 2023-07-26, 16:32:

gerwin wrote on 2023-07-26, 15:00:

Failure to run at higher FSB or failure to run at all may be a sign of aging capacitors on the motherboard.
Does the motherboard work properly with other processors?

Yes I've tried running it with a Intel Pentium MMX before and it ran fine. I also used to have a amd k6-2 in it before and that also worked without any issues.

You can test 100MHz FSB with both these processors, for that configure the multiplier to a low setting like 2x.

Tried but without any success, for some reason the cpu works on another motherboard. Still running at 66 mhz but at least It works.

gerwin wrote on 2023-07-26, 16:40:

Florian J wrote on 2023-07-26, 16:32:

gerwin wrote on 2023-07-26, 15:00:

Failure to run at higher FSB or failure to run at all may be a sign of aging capacitors on the motherboard.
Does the motherboard work properly with other processors?

Yes I've tried running it with a Intel Pentium MMX before and it ran fine. I also used to have a amd k6-2 in it before and that also worked without any issues.

You can test 100MHz FSB with both these processors, for that configure the multiplier to a low setting like 2x.

Don't use 2X multi on K6-2/3 CPUs as CPU turns it to 6X 😉

Florian J wrote on 2023-07-26, 16:57:

gerwin wrote on 2023-07-26, 16:40:

Florian J wrote on 2023-07-26, 16:32:

Yes I've tried running it with a Intel Pentium MMX before and it ran fine. I also used to have a amd k6-2 in it before and that also worked without any issues.

You can test 100MHz FSB with both these processors, for that configure the multiplier to a low setting like 2x.

Tried but without any success, for some reason the cpu works on another motherboard. Still running at 66 mhz but at least It works.

What is the motherboard and revision. Not all motherboards support K6-2+. Otherwise you have to reconfigure the motherboard for new CPU.

kixs wrote on 2023-07-26, 17:08:

Florian J wrote on 2023-07-26, 16:57:

gerwin wrote on 2023-07-26, 16:40:

You can test 100MHz FSB with both these processors, for that configure the multiplier to a low setting like 2x.

Tried but without any success, for some reason the cpu works on another motherboard. Still running at 66 mhz but at least It works.

What is the motherboard and revision. Not all motherboards support K6-2+. Otherwise you have to reconfigure the motherboard for new CPU.

P5TX-Bpro

I think I found the issue. The motherboard does not support 2.0 cpu voltage, which is what the cpu is rated for.

I hope it will still work stable as the motherboard over-voltage it. It's best to get one super socket 7 motherboard with AGP slot - late revision for full support of + processors.

Alright so I got a Pentium mmx working on the motherboard again, I will update the bios to the latest version and if that doesn't help I'll use Jan Steunebricks patched bios.

Thanks for all the help 👍

Florian J wrote on 2023-07-26, 18:22:

Alright so I got a Pentium mmx working on the motherboard again, I will update the bios to the latest version and if that doesn't help I'll use Jan Steunebricks patched bios.

Thanks for all the help 👍

The latest official version does not support K6Plus CPUs, so that will not change behaviour. That's why Jan has patched the BIOS.

For what it's worth I have the similar Tekram P5MVP-A4 motherboard and behaviour was exactly the same before flashing the patched BIOS. Afterwards it happily ran with my K6-3+ CPU.

Tekram P5MVP-A4 is not similar board to P5TX-Bpro at all.

kixs wrote on 2023-07-26, 19:11:

Tekram P5MVP-A4 is not similar board to P5TX-Bpro at all.

Not P5TX-Bpro, but the P5M4-M+ OP was talking about first and that he is actually trying to get the CPU working on now, after finding it boots on the P5TX-Bpro but that one overvolts it badly.

MVP3 full ATX vs MVP4 uATX, but otherwise both similar last-gen (S)S7 platforms from Tekram with very similar BIOS with the exact same BIOS limitations that are fixed by Jan's patch (K6Plus and 64->128GB HDD limit)

Florian J wrote on 2023-07-26, 17:30:

I think I found the issue. The motherboard does not support 2.0 cpu voltage, which is what the cpu is rated for.

The first board you mentioned, P5M4-M+, seems to support 2,0V as the minimum. With all jumpers removed that is. Not directly illustrated as such, but it figures.
In general though, for socket 7: When you are unsure of CPU voltage settings, then don't try anything until you are sure. You can fry your Voltage-Regulator and/or CPU with the wrong setting. It is not user friendly like more modern motherboards.

dionb wrote on 2023-07-26, 19:59:

kixs wrote on 2023-07-26, 19:11:

Tekram P5MVP-A4 is not similar board to P5TX-Bpro at all.

Not P5TX-Bpro, but the P5M4-M+ OP was talking about first and that he is actually trying to get the CPU working on now, after finding it boots on the P5TX-Bpro but that one overvolts it badly.

MVP3 full ATX vs MVP4 uATX, but otherwise both similar last-gen (S)S7 platforms from Tekram with very similar BIOS with the exact same BIOS limitations that are fixed by Jan's patch (K6Plus and 64->128GB HDD limit)

Indeed. I somehow missed he tested with two boards 😉