View Full Version : Previous shut down due to thermal event

21-10-2007, 12:27 PM
Hi, can anyone help (my IT dept at work tried everything here)...

My Dell Optiplex GX270 is about 3 years old and I have never had any problems. I use Windows XP and have all of the standard hardware that came with the PC.

Everytime I turn on the computer I get the error message "Previous shut down due to thermal event" press F1 to continue or F2 for setup.

When I try to start in normal mode or from the last known good configuration it shuts down on its own. I have tried it after leaving the PC off for 48 hours and it is in a normal household environment.

If I start in any safe mode it works fine but takes a little while to boot up. It then works fine and will stay on for days but I have limited use of the software as you can imagine.

I noticed that when I boot with command prompts it hangs for ages on the "BTHIDMGR.SYS" prompt before booting.

Both fans are working, I have scanned for virus' with 3 types of software and done the usual defrag and removed all unwanted software. I am hoping not to have to format the C/Drive.

Finally, it did work normally a couple of days ago but after about 2hrs it just shut itself down. Personally I am wondering if there is a temperature switch that the system checks prior to boot that is not working and therefore the system won't boot and perhaps safe mode doesn't require the 'check' but any help that can be offered would be so much appreciated.

Many Thanks

21-10-2007, 07:12 PM
Sounds like its overheating. Get a can of compressed air and give it a good dusting inside.

Some of the optiplex range have a speed sensor on the cpu fan, if the fan drops just a few % the bios complains.

If nothing else works, try a new heatsink/fan.


05-01-2008, 12:03 AM
I had an Optiplex do the same. Bad news is it was the capacitors on the mobo. Look for bulging out at the tops of them, sometimes yellow discolour from leakage.

05-01-2008, 12:10 AM
Since the computer runs fine in Safe Mode, then the problem isn't likely hardware related.

Either a driver or one of your Normal Mode startup programs is using up too much of the cpu causing it to overheat. Well that's my guess anyway:)

Go into Normal Mode and ctrl-alt-del to access Task Manager and click on Processes. At idle, cpu usage should be no more than about 5%. Keep an eye on it, as it may take a while for the suspect process to appear so you can identify it.

05-01-2008, 12:38 AM
In regards to it being caused by a driver:

BTHIDMGR.SYS is in reference to Bluetooth. This won't start in Safe Mode, but in Normal mode
the BT driver will load and may be causing a loop in the cpu cycles. That would cause the cpu to overheat.

As another test, go into msconfig from Safe Mode and disable anything BT, then try Normal Mode.

06-01-2008, 02:04 AM
I just replaced the fan on a optiplex with the same issue and its fine now. Like I said they can be oversensitive about fan speed.

Take a look at the number on top of the fan, if you google it you should find a couple of places that sell them. I got mine from a friend who scraps computers.


06-01-2008, 02:08 PM
On my optiplex that went bad (if memory serves me right)I could also boot in to safe mode. I thought that it would be a heat sensor or switch gone wrong as it all happeened much too fast it seemed to be heat (fan) related.
Certainly check the fan but while you have got the lid open check the capacitors, that was my problem and from the chatter it was a common problem


Ah yes the GX270...IMHO one of the worst HW releases by Dell. Dell when maufacturing the motherboards used capacitors that were manufactured incorrectly by a 3rd party supplier. This is very easy to diagnose. Open your case and look near the heatsink/fan area you will see cylinders that have an 'X' on top. If ANY of these are swollen or have orange stuff on top then you need a new mobo.

I believe that when the caps go bad that the power lvl to the CPU fan is drained and it can't keep up with the heat. I have diagnosed and repaired 100 of these units so far with 95% being this exact problem. The other test is to put your hand near the back and see if the fan is blowing at all.


Hope for you that it turns out to be simple but it was a common failing.
I have had 3 boards all fail in this way (only one was a Dell) and I suppose the good thing about it is ....Computer fault... open lid... capacitors leaking,,, new mobo. So it is a simple diagnosis and straightforward (though expensive)fix.
Good luck

06-01-2008, 02:35 PM
We see a lot of motherboards with bad caps, putting a component that can dry-out next to the big heatsink has always seemed a bit daft to me. You can get heat tolerent caps but they are more expensive so dont get used on home systems. The first epia micro atx boards used to suffer from this problem a lot.

I guess I was lucky, it was just the speed sensor in the fan.