Southbridge Overheating? Bad motherboard? PSU? (MSI P6N-FI nForce 650i)

[Syndicate]

Hey fellas,

I don't typically ask for tech help on here but I'm a little stumped on this one.


Situation:

Using PC as normal, doing a disk clone with Acronis. Plugged in new drive for cloning (SATA) while system was running.

About 30 minutes into the process the system suddenly shut down.

Reboot.

Shut down after about 10 minutes.

Figured ok, that's strange... But I'd been playing with the BIOS the previous day and figured I tripped a setting somewhere. Reset CMOS.

Boot, post, die.

Hmm. Re-check all cables, remove unneeded accessories.

Boot, die (no post).

Odd.

While checking around I felt across the Southbridge heatsink (little aluminum crap heatsink) and it was absolutely roasting hot... Not 50C hot, finger-tip burning hot.

Rechecked everything, let it cool off. Unplugged all unneeded accessories.

Post, boot (windows), die.

Heatsink already warm (guess ... 40C).

So that's where I am at. It won't post. Have removed battery to reset CMOS, haven't changed much recently. Clearly its either the mobo or the PSU.

One thing I noted is that if I unplug the power connector to the 4-pin/8-pin on the motherboard (currently using a 8-pin connector from the PSU) - the system will turn on and stay on (but of course do nothing).

Specs:

550W SunbeamTech NUUO Series (actually a good PSU, hopefully)
MSI P6N (nForce 650i chipset) Motherboard
C2D E6300 @ 1.86 GHz (not OC'd yet), AC Freezer Pro 7
2GB GeiL PC6400
2x 250GB Seagate 7200.10 SATA
20x DVD/RW IDE
256MB PCI-E 7800GT (no OC)
Floppy
2x 120mm case Fans in Lian Li PC7-B

Let me know if anyone has any clues

[leej1982]

a hot heat sink is normal, but a extremely hot unable to touch heat sink normally means the motherboard has suffered a surge or has been damaged in some way this is from personal experience

[Smoove910]

Are you sure Acronis didn't bork your Windows install? Have you tried unplugging all harddrives and see if it boots (and stays running) into the BIOS?

[mlc]

do you have a psu you can try from another computer? Sounds like its definitely a PSU or MOBO issue.. most likely a bad atx 12v regulator on the board.. but it would be nice to confirm with another psu

[daveybrat]

Where did you get the idea that a Sunbeam power supply was a good unit? From the reviews i've read they seem pretty bad. And i've never heard of the company, so it's likely just another generic unit.

First thing i'd try is another reliable brand first.

[denis280]

Originally Posted by daveybrat

Where did you get the idea that a Sunbeam power supply was a good unit? From the reviews i've read they seem pretty bad. And i've never heard of the company, so it's likely just another generic unit.

First thing i'd try is another reliable brand first.

Swap.psu

[hoorah]

I would say that because your uptime becomes progressively shorter the longer the system is on that its a heat related issue, especially since you said the SB is quite hot.

Here's what I would do: First, I'd recheck the thermal goo between the heatsinks on the NB and SB. Then, since you suspect the SB, I'd see if I could either wedge a small fan on top of it or just hold it in place temporarily, and see if the system will boot. If yes, watch the temperature sensors and see if anything seems out of the ordinary.

[VirtualLarry]

I burned out a friend's 650i board attempting to OC it, using some "guides" I found on the internet, that told you to juice up the NB/SB voltages. It cooked itself.

Possibly the same thing is happening or has happened here.

That PSU is likely not too great either.

I vote for adding a fan to the SB, and if that doesn't help, try swapping PSUs with a known good brand/unit.

[sm625]

Originally Posted by Syndicate

Using PC as normal, doing a disk clone with Acronis. Plugged in new drive for cloning (SATA) while system was running.

You literally plugged in a sata drive while it was running? You could have fried your sata controller, which is probably on the southbridge. Your only hope is to get that sucker really cold, and get into the bios and disable the sata controller before it gets too hot. But even that might not work. It all depends on what you fried exactly, or how extensive the damage is.

If you can manage to disable the sata controller, and get windows to boot/install off pata and run somewhat normally, then you could get a sata card. Or just stick with pata.

[Zap]

Originally Posted by Syndicate

550W SunbeamTech NUUO Series (actually a good PSU, hopefully)
MSI P6N (nForce 650i chipset) Motherboard

The PSU tested well in load test reviews, but didn't age well. Too many of them died after a few years, often with sagging voltages.

The motherboard is also suspect, as it is pretty old and older boards tend to develop capacitor aging problems.