I understood that the chip is the southbridge and if it is super hot, means that it is shorted…
Bad news I guess.

I noticed on bios that 5V rail was not ok (4.something) but being less than 5V I was not thinking it was a problem.
Strange, as I am using a robust Corsair SF600.
Guess those cards need older PSU with different power deliveries (?).

Am I doomed now?

Another update, with an AGP card, the Southbridge is not immediately so hot anymore.
But waiting a couple of minutes it become super hot again.
It is not that it gets hot gradually, but immediately after some minutes.

Maybe there is something before the southbridge, a resistor or something, that could be faulty?

I think this may indeed be related to the ServerSet III HE chipset. As far as I know, some Intel SDS2 motherboards have also suddenly failed in a similar way. I have a faulty Intel SDS2 that also exhibits similar phenomena. It suddenly freezes during normal operation and then cannot be started again. The NB, SB and IOB are all abnormally hot. I checked the power supply circuit and even replaced all the LDOs of the chipset power supply, but it didn't solve the problem.

See if anyone else has encountered similar problems. I also want to fix my SDS2. This is terrible 🙁

Have you got the 6pin AUX connector plugged in?

Ive seen your build thread, is that how it still looks, with the ATX power going into the secondary power connector and nothing plugged into the AUX connector?

Never used the AUX connector and the secondary atx is for redundancy. I do not think it is related to the fault.
Guess I had just bad luck this time

The AUX connector supplies power to the PCI cards.

I dont recall this chip getting even warm on my boards... I have one coming in the mail shortly, when I test it out I will double check.

For the record the 5v supply is "allowed" to droop a little bit. At most 10%. Past that things get wiggy, quick. But a low voltage will not cause parts to overheat.

These boards are just fine with new power supplies. The biggest 5v load comes from the CPU. And this era of boards started using the 12v aux power connector for that.

luckybob wrote on 2024-09-02, 17:46:

I dont recall this chip getting even warm on my boards... I have one coming in the mail shortly, when I test it out I will double check.

For the record the 5v supply is "allowed" to droop a little bit. At most 10%. Past that things get wiggy, quick. But a low voltage will not cause parts to overheat.

These boards are just fine with new power supplies. The biggest 5v load comes from the CPU. And this era of boards started using the 12v aux power connector for that.

Yes I know.
I think I shorted the southbridge somehow.
Change it is totally beyond my expertise
I gave it away.

luckybob wrote on 2024-09-02, 17:46:

I dont recall this chip getting even warm on my boards... I have one coming in the mail shortly, when I test it out I will double check.

For the record the 5v supply is "allowed" to droop a little bit. At most 10%. Past that things get wiggy, quick. But a low voltage will not cause parts to overheat.

These boards are just fine with new power supplies. The biggest 5v load comes from the CPU. And this era of boards started using the 12v aux power connector for that.

Are you sure?
Not 3.3v and 5v ?

I can 100% confirm the cpu is on the 5V rail. at least on these SM boards. But I have a slightly newer SDS2 and it requires the 24pin with 12v aux. it was right there at the transition.

The aux connector is directly connected to the ATX 20 pin on this SM board. So its not required. its just easier on the old 20-pin connector when you have the AUX connected

new supplies will be just fine. if you are worried, you can always connect a 2nd power supply.