Tried multiple power supplies?

jakethompson1 wrote on 2022-07-16, 02:37:

Tried multiple power supplies?

Yes, with a much older power supply from around 1999. I updated the post; thanks for the suggestion, though.

Just now I tried lowering the FSB to 60MHz, but that didn't help, unfortunately.

Tried a few more things and updated first post. Nothing has helped so far.

It is very strange - With a cold boot, the board can go further - loading Windows, booting from a floppy disk, or messing around with BIOS settings before it finally freezes. However, after successive boots the time to lockup gets shorter and shorter becoming only 3-5 seconds before freezing. I've never experienced this behavior before.

I bought a re-flashed BIOS with the latest release - we'll see how it goes in a few days.

Is this system in a case ?
If not, what is it laid on ?
Do not attempt to flash a new bios with this issue.

Try disabling any cache on the mobo
Check for shorted pins on onboard chips (e.g. bent leg shorted to neighbor)

JustJulião wrote on 2022-07-19, 14:42:

Is this system in a case ?
If not, what is it laid on ?

No, it's open air at the moment resting on a raised surface with cardboard underneath the board. I haven't had any other issues with any other motherboard, but do you think I should try something else?

drosse1meyer wrote on 2022-07-19, 14:45:

Try disabling any cache on the mobo
Check for shorted pins on onboard chips (e.g. bent leg shorted to neighbor)

There's no cache on this motherboard as it's a PII. Do you mean go into the BIOS and disable for the PII itself?

I'll check again for any bent pins - it's possible I didn't look close enough.

Thanks for the suggestions!

Meatball wrote on 2022-07-19, 14:48:

JustJulião wrote on 2022-07-19, 14:42:

Is this system in a case ?
If not, what is it laid on ?

No, it's open air at the moment resting on a raised surface with cardboard underneath the board. I haven't had any other issues with any other motherboard, but do you think I should try something else?

I've had the exact same issue and it ended up being the power supply. Maybe this one is more sensible, if the 4 you tried are old, maybe try a newer one.
Also I edited my first post : do not try to flash the bios (except if you can do that on an eprom programer). I don't think it would resolve the issue anyways.

JustJulião wrote on 2022-07-19, 14:51:

Meatball wrote on 2022-07-19, 14:48:

JustJulião wrote on 2022-07-19, 14:42:

Is this system in a case ?
If not, what is it laid on ?

No, it's open air at the moment resting on a raised surface with cardboard underneath the board. I haven't had any other issues with any other motherboard, but do you think I should try something else?

I've had the exact same issue and it ended up being the power supply. Maybe this one is more sensible, if the 4 you tried are old, maybe try a newer one.
Also I edited my first post : do not try to flash the bios (except if you can do that on an eprom programer). I don't think it would resolve the issue anyways.

2 were newish (2010s) and 2 were older (around 1999).
Yes, I definitely have an urge to flash it, but I also figure it won't work; I ordered a new chip; it should be here tomorrow or Thursday.

Meatball wrote on 2022-07-19, 14:49:

There's no cache on this motherboard as it's a PII. Do you mean go into the BIOS and disable for the PII itself? […]
Show full quote

drosse1meyer wrote on 2022-07-19, 14:45:

Try disabling any cache on the mobo
Check for shorted pins on onboard chips (e.g. bent leg shorted to neighbor)

There's no cache on this motherboard as it's a PII. Do you mean go into the BIOS and disable for the PII itself?

I'll check again for any bent pins - it's possible I didn't look close enough.

Thanks for the suggestions!

That's my fault, need more coffee 😀 Worth a shot anyway I guess, it's easy (and free)...

drosse1meyer wrote on 2022-07-19, 15:05:

Meatball wrote on 2022-07-19, 14:49:

There's no cache on this motherboard as it's a PII. Do you mean go into the BIOS and disable for the PII itself? […]
Show full quote

drosse1meyer wrote on 2022-07-19, 14:45:

Try disabling any cache on the mobo
Check for shorted pins on onboard chips (e.g. bent leg shorted to neighbor)

There's no cache on this motherboard as it's a PII. Do you mean go into the BIOS and disable for the PII itself?

I'll check again for any bent pins - it's possible I didn't look close enough.

Thanks for the suggestions!

That's my fault, need more coffee 😀 Worth a shot anyway I guess, it's easy (and free)...

We've all been there! haha..

Well, the replacement chip arrived today, but the board won't POST at all. The new chip gets ferociously hot almost immediately (just as if it were plugged in backward), I need to power down PDQ.

I did try to reverse the direction just for the heck of it, but the expected overheating occurred. I've contacted the seller for further assistance.

When the old chip is put back in (just to make sure I didn't fry anything), board POSTS, but continues to lock up shortly thereafter.

Those capacitors look lovely and absolutely fine, but you cant go only by looks. Either use oscilloscope to look at Vcore and other supply lines, or just replace them blind.
altho
>However, after successive boots the time to lockup gets shorter and shorter
with bad capacitors its often the other way around, with capacitors getting slightly better when warm. Getting worse might mean something is overheating - do a finger test and look for hot spots after board refuses to start.

rasz_pl wrote on 2022-07-22, 00:28:

Those capacitors look lovely and absolutely fine, but you cant go only by looks. Either use oscilloscope to look at Vcore and ot […]
Show full quote

Those capacitors look lovely and absolutely fine, but you cant go only by looks. Either use oscilloscope to look at Vcore and other supply lines, or just replace them blind.
altho
>However, after successive boots the time to lockup gets shorter and shorter
with bad capacitors its often the other way around, with capacitors getting slightly better when warm. Getting worse might mean something is overheating - do a finger test and look for hot spots after board refuses to start.

Thanks! I've tried finger testing the larger chips, but I should probably check everywhere.

There is a "CPU Thermal Protection" chip located near the CPU Slot. If temps reach 55C, a warning is supposed to be displayed from the BIOS during POST, and then the CPU is throttled automatically. No warnings have ever been displayed and this chip has also been cool to the touch. However, I wonder if this chip is malfunctioning? If not, it's what I hope an updated BIOS might resolve. Or perhaps this thermal sensor cut be surgically cut out?

Slot 1 contacts, both sides, get hella tweaky, and it's only after the last time you clean them they decide to work.

to automagic throttling with Pentium2, its all software controlled and afaik would not look like broken motherboard, you would hear the beeps if its implemented at all in your board

rasz_pl wrote on 2022-07-22, 02:28:

to automagic throttling with Pentium2, its all software controlled and afaik would not look like broken motherboard, you would hear the beeps if its implemented at all in your board

From the manual:

2.6 CPU Thermal Protection
This mainboard implements special thermal protection circuit under the CPU
heatsink. When temperature is higher than 55 degree C, the CPU speed will
automatically slow down and there will be warning from BIOS and also ADM
(AOpen Desktop Manager, similar as Intel LDCM), if ADM is installed.
It is automatically implemented by BIOS and ADM, no hardware installation is
needed.