CPU overheats in less than a minute

[JBS]

System:
CPU: AMD X2 4850e 45-watt dual core CPU
MB: Gigabyte GA-MA78GM-S2H rev 1.0
HSF: OCZ Vendetta 2


When I turn on my computer, the CPU temp rises until the computer turns itself off, which usually takes less than a minute. The temps of each core (according to CoreTemp) keep rising until they are both over 100C, at which point the computer shuts itself down. Readings from Hardware Monitor and Speedfan also show core and CPU temps over 100C, however HDD and System temps are normal (30's). This all started happening out of the blue (everything was fine one day, no hardware or software changes, then this started happening).

I thought maybe there was poor contact between the CPU and heatsink, or the heatsink had become damaged in some way. I checked the heatsink for damage or bad HSF-CPU contact (none, good contact), re-seated it twice with TIM, and made sure of good contact between the heatsink and CPU. However the CPU still overheats in less than a minute.

Also, when the temp readings are over 100C, the heatsink does not even feel warm to the touch, so I'm not sure if the CPU is actually overheating.

From the time when the computer worked fine to when it now quickly overheats, no changes of any kind were made. It just worked fine one day, and overheats in less than a minute the next.

Has the CPU possibly gone bad, or could the problem be the motherboard, or even the power supply?

 

[myocardia]

Originally posted by: JBS
Also, when the temp readings are over 100C, the heatsink does not even feel warm to the touch, so I'm not sure if the CPU is actually overheating.

It takes longer than 60 seconds for a heatsink to heat up. Kind of like a car's engine; run it for 60 seconds or less, and nothing will be hot, although the exhaust will have started warming up a bit.

Has the CPU possibly gone bad, or could the problem be the motherboard, or even the power supply?

Are you certain that your CPU's heatsink fan is actually spinning? If it is, you need a new motherboard, assuming you haven't screwed up horribly when installing the heatsink.

 

[alcoholbob]

Could there be built-in motherboard protection that just reboots the system when the CPU reaches a certain threshold? (even if the reading is way off).

 

[FalseChristian]

It sounds like your cooler isn't touching your CPU. Check to make sure that it does.

 

[deamer44]

I had this problem, check if all of your push pins are correctly inserted, and that no wires are stopping your fan from running.
Hope this helps

 

[Raduque]

He said he checked and reseated the heatsink twice with new TIM each time. I'm not thinking it's a contact issue or a fan issue.

My bet is the mobo temp sensor is screwey..... see if you can get into the BIOS long enough to kill the thermal protection.

 

[JBS]

I decreased the voltage from 1.25v to 1.15v, and the temperature readings did go down. However they are still way higher than they should be. Also, I had re-seated the heatsink twice and made sure of good contact, so that isn't the issue.

idling @ 1.15 volts: core #0 is 58 C, core #1 is 43, CPU temp is 75 C

Does this seem more like a problem with the CPU or the motherboard? I'm not very good with computers so I need as much help as I can get here.

 

[JBS]

Does the CPU itself have temp sensors, or does only the motherboard have temp sensors.

I ask because when programs like CoreTemp, Everest, Speedfan, and Hardware Monitor are all reporting temps over 100c for the CPU, the heatsink does not even feel warm to the touch. Would this point to bad CPU sensors, or bad motherboard sensors.

 

[VirtualLarry]

I wonder if the IHS of the CPU is not making good contact any more with the CPU core die. That could explain things.

 

[myocardia]

Originally posted by: JBS
Does the CPU itself have temp sensors, or does only the motherboard have temp sensors.

The sensors are in the CPU itself, however, that doesn't help you any, because the motherboard has to interpret the data that the CPU is sending. So, either of them could be screwed.

 

[nyker96]

the symptoms point to bad seating of HSF, reseat that thing before you try another time or you might be in danger of frying that lovely cpu.

 

[JBS]

Does the CPU sensor monitor CPU temp only, or does it measure core temps too (core 0, core 1). I'm getting drastically high temp readings for not just the CPU, but for both cores. If the CPU sensor only monitors CPU temp but not cores, the problem may be something other than the CPU.

The heatsink (OCZ Vendetta 2) and fan is working fine. I have re-seated the heatsink twice and made sure of good solid contact between CPU and HSF. I also tried using another heatsink, and had the same (bad) results. Also, with the temp readings this high, I tried touching the heatpipes just above the HSF/CPU contact point, and they were barely warm.

These are my readings from different programs:

@1.10 CPU voltage:

Hardware Monitor:
Temp0: 34c (don't know what this is)
Temp1: 73c (don't know what this is)
Temp2: 90c (don't know what this is)
Core #0: 43c
Core #1: 58c
HDD: 36c

Core Temp:
Core #0: 58c
Core #1: 43c

Everest:
Motherboard: 73c
CPU: 90c
Core #1: 58c
Core #2: 43c
Aux: 34c

Gigabyte EasyTune5 Pro:
System: 34c
CPU: 73c

How would I go about isolating whether the CPU has gone bad, or if possibly the motherboard is bad.

 

[myocardia]

Originally posted by: JBS
Does the CPU sensor monitor CPU temp only, or does it measure core temps too (core 0, core 1). I'm getting drastically high temp readings for not just the CPU, but for both cores.

The CPU's temp sensors read all CPU temps, of course. Your core temps are fine, BTW, except they show that you need more practice applying thermal paste. The cores shouldn't be more than a couple of degrees apart; 15C is way too much of a spread.

These are my readings from different programs:

@1.10 CPU voltage:

Hardware Monitor:
Temp0: 34c (don't know what this is)
Temp1: 73c (don't know what this is)
Temp2: 90c (don't know what this is)
Core #0: 43c
Core #1: 58c
HDD: 36c

Core Temp:
Core #0: 58c
Core #1: 43c

Everest:
Motherboard: 73c
CPU: 90c
Core #1: 58c
Core #2: 43c
Aux: 34c

Have you updated your BIOS to the latest version for your board? If you're running a 45nm chip, and your board thinks it's running a 65nm chip, it may very well just be interpreting the output from the CPU's sensors incorrectly.

See, the CPU is where the sensors are located, but the motherboard has to interpret the readings from it, to know what to report to the BIOS/software. If either can be screwed up, you'll get incorrect readings, and yeah, that can even include if the motherboard doesn't recognize the processor that it's running.

How would I go about isolating whether the CPU has gone bad, or if possibly the motherboard is bad.

Before you give up, and start RMAing parts, try reseating your heatsink one last time. This time, use this guide: How to apply TIM to HDT heatsinks. You may very well just not be getting any thermal paste at all over the center of your processor, which is where your "CPU Temp" sensor is located. That's also the sensor that your motherboard uses to determine whether your CPu is running too hot, and needs to shut down to protect it.

If that doesn't help, the only way to tell which part needs to be replaced is to replace one of them. You could try your processor in another motherboard, or you could try another processor in your motherboard. Short of that, you'll just have to replace one or both of them.