INTEL 82801EB Controller chip keeps getting hot after computer is switched off

[bryno]

The motherboard is Medion MD-8088. After replacing "dead" PSU the motherboard

is not starting up.

I have removed all periferals leaving only motherboard and PSU.

I have noticed that when the PSU is plugged into motherboard the INTEL 82801EB Controller chip is

starting to warm up even before the power switch on the motherboard is switched to "ON" to start the PSU.

This behaviour is observed with 2 different PSU's on 2 different Medion MD-8088 motherboards.

Any idea what could cause this behaviour? Is this faulty PSU? Is this "burned" motherboard?

I don't think it is normal that a controller chip is warming up when computer is switched off but I am still puzzeled how can this be observed on 2 different motherboards with 2 different PSU's

All suggestions how to solve this are more then welcome.

 

[PeterB]

Some peripheral interfaces, the LAN for one, are active even when the machine is powered down.  Such devices are powered from the 5VSB line, which is not switched.

[bubbaQ]

When a mobo is turned off, it still uses thr 5-v power to do things like keep the NIC on to listen for a WOL packet, and to do other ACPI event handling.

[bryno]

Some peripheral interfaces, the LAN for one, are active even when the machine is powered down.  Such devices are powered from the 5VSB line, which is not switched.

 

Thanks PeterB.

It sounds resonable that the mobo has some power to do the stuff when powered down. What worries me is that this INTEL 82801EB Controller chip is getting really hot. Don't know how hot but after a while I can not keep my finger on it without getting pain. I have never noticed this before, just now, when I am attempting to solve the problem that the mobo is not posting to video card. It Looks like the mobo and CPU are working. When memory is removed mobo issues the warning beep but after the memory is placed on board again no beeps are heard, even when the video card is not present, And still no post to video card when it is placed again.

 

When a mobo is turned off, it still uses thr 5-v power to do things like keep the NIC on to listen for a WOL packet, and to do other ACPI event handling.

Thanks bubbaQ,

Just like I said to PeterB - mobo would not post to video card. I have removed all peripheral interfaces except those which are integrated. After removing Wi-Fi card I have discovered that the Intel controller is getting hot when board is switched off [ the controller chip is situated under the WiFi card].

In the meantime I have even used diagnostic card to trace the issue. It shows some activitity in the beginning and halts on BIOS code 25 - Interrupt vector loading in progress.

 

[c234rmf]

Do you have any USB add on ports plugged in or USB devices plugged in?  A lot of motherboards support wake functions over USB using the standby power so if you have some sort of fault maybe this is where the power is being dissapated.

Also i dont know your capabilities - is it possible you have a misplaced standoff shorting out something on the bottom of the board?