overheating southbridge/chipset

[byteexp]

no boot/dead board, need help in finding the fault

motherboard 1 (ecs s754)
died after finding bulding caps, then no boot
recapped but had overheating chipset, with power, 2 vrm/mosfet (near cpu socket)has no measure voltage, others are good

motherboard 2
automatically turns-on, measured voltage, some caps has voltage measured, while others dont have.

does torroid coil fail? if yes, what are tell-tale signs
too hot chipsets?what are possible causes
what makes board to automatically power on after plugging atx power connectors.


thanks

[stretch0069]

Re: overheating southbridge/chipset

moved it in here. hopefully someone will be along shortly to answer your questions.

[stevo1210]

Re: overheating southbridge/chipset

too hot chipsets?what are possible causes

How hot is the chipset we are talking about? Is it so hot that when you put your finger on it, it will burn your finger?
If that is the case then you might as well throw the board in the bin or use it for parts because the chipset is internally shorted. This is usually caused when you use a no-name PSU (Like a DEER etc.) and overvoltage on the +5VSB or excess ripple current occurs.
I've had quite a few people bring their PCs in with the same problem. Usually the PSU is a no-name generic one with bad caps which in turn burns the southbridge chipset.

[zandrax]

Re: overheating southbridge/chipset

Usually the PSU is a no-name generic one with bad caps which in turn burns the southbridge chipset.

I agree; the second more likely cause is a badly installed heatsink (e.g. no thermal paste) or a dust clogged fan on really hot chipsets like nVidia nForce 2, 3 and 4.
Can you post any detail about the boards? Photos are appreciated.

Zandrax

[byteexp]

Re: overheating southbridge/chipset

thanks for the reply, 1 board is asrock socket754 with nvidia chipset

the other one is ecs nforce 3a s754, yes, the chipset is so hot that it will burn your fingers when you try to touch it.

the other one i think used to have its chipset overheat, but after further testing and i think recapped it again have had the chipset return to normal temp.

btw. again, thanks for the help

[bgavin]

Re: overheating southbridge/chipset

If you have a PCI slot unused, you might consider a Rocket cooler.

Link to Newegg

I use this for passive cooled video cards (MSI, etc) that run too hot. These coolers are a bargain at $10, and worth the money. On the slow setting, they run quiet and move a good amount of air.

A side benefit of these, is most Southbridge and numerous Northbridges are also cooled. It comes with a 2nd bracket to allow down draft as well as side draft operation. It has a plastic tang that sticks into an unused PCI slot, but does not draw power... just a locator tang. It bolts in like any PCI card, and uses a Molex power connector.

[mikail13]

Re: overheating southbridge/chipset

i have same issue.

my msi g31m3 board doesn't post. no action...

only south bridge is overheat.

the caps around the rem and south bridge they must be 1000 mF is overrated.

4800 mF or 34 mF..

after i change i see no effect. South bridge overheats anyway.

but one mosfet don't the for earlier.

if i recapp 470 mF? there are 6 caps.

[stj]

Re: overheating southbridge/chipset

is it hot enough to burn yourself ?
because if it is, it's shorted out.