[XJDHDR]

Hello everyone

A friend of mine recently gave me his old computer, which I am thinking of restoring due to the fact that it is better than what I currently have. I soon noticed that the computer kept turning itself off after a minute or so. After some testing, I worked out that it kept turning off because it was protecting the CPU from overheating. To confirm, I went into the PC's BIOS as soon after the computer started as I could. The temperature read 80*C and quickly rose to 94*C at which point the PC turned off.

By putting a piece of aluminium foil between the heatsink and CPU, I managed to make the temperature stop rising at 75*C. Another friend who was visiting at the time suggested that the high temperature was because the CPU fan was blowing air into the heatsink instead of away from it. Does this sound right to you? Could the problem even be a faulty thermometer on the motherboard, causing the motherboard to protect the CPU from a threat that doesn't exist? I would really like to get this PC in a properly running state again. Your help will be greatly appreciated.

Kind regards

[etaf]

By putting a piece of aluminium foil between the heatsink and CPU, I managed to make the temperature stop rising at 75*C.

you could make sure the heatsink is the correct way around - if the wrong way round, it does not make contactcorrectly with the CPU
also you need thermal paste between the heatsink and CPU, which would be much better than silver paper...

Does it feel very hot - BE Very CAREFUL, heat and electrical - you should be able to tell if running at 30-40c rather than 75-80c just by your hand near it.

blowing air into the heatsink instead of away from it.

NOT Sure, but again, you should be able to tell
Make sure the Fan is clean of dust etc

[win2kpro]

The bottom of the heatsink and the top of the processor need a good quality thermal compound between them to transfer heat, not aluminum foil. Both surfaces need to be perfectly clean before applying the thermal compound.

Blowing air into the heatsink is the preferred method of cooling. Both pushing air into the heatsink or pulling air into the heatsink will cool it, however by pushing air is a better method since it tends to push dust away from the heatsink, whereas pulling air into the heatsink tends to pull dust into the heatsink.

[XJDHDR]

Originally Posted by etaf

you could make sure the heatsink is the correct way around - if the wrong way round, it does not make contactcorrectly with the CPU
also you need thermal paste between the heatsink and CPU, which would be much better than silver paper...

How do I tell if the heatsink is the right way round? There isn't any paper in the foil I used, it is pure aluminium. I could still try thermal paste though. I just need to know where to get some (in South Africa).

Originally Posted by etaf

Does it feel very hot - BE Very CAREFUL, heat and electrical - you should be able to tell if running at 30-40c rather than 75-80c just by you hand near it.

...Make sure the Fan is clean of dust etc

The fan and heatsink are completely clean, my brother and I made sure of that. I started the computer and let the PC stay in the BIOS for about 5 minutes with the CPU at 75*C. After this and with the PC still turned on, I could still touch the bottom of the side of the heatsink and only feel a minuscule amount of heat.

I also noticed something else. I'm not sure exactly how fast a CPU heats up but it only takes about 8 seconds for me to get into the BIOS and in that time, the CPU supposedly heats up to 60*C while the motherboard temperature still reads 25*C.

@Win2kPro
That is probably true but I needed a quick solution to my heat problems. I didn't think that a fan blowing the wrong way would cause a 60*C+ rise in temperature too.

[win2kpro]

A fan pulling air through the heatsink rather than pushing air through a heatsink will not cause a 60°C rise in temperatures, however operating without thermal compound or a thermal pad will cause a rapid rise in temperatures.

Using aluminum foil is not a thermal solution.

[etaf]

{its been a couple of years now since i built PCs } but on these older machines theres a notch running along one edge of the CPU and also a matching ridge on the heatsink - so if round the wrong way (which was a problem, i have seen a few times - also on this forum) the heatsink would be slightly off the cpu at one end.
BUT as i say not sure about modern configurations.
you can see this here

however, I would suggest paste rather than the pad shown here - dont use too much as that can cause issue to

[BruinBeer]

Hi XJDHDR
You can try one of these online computer stores:
www.sybaritic.co.za
www.titan-ice.co.za
www.comxcomputers.co.za
Posted via Mobile Device

[XJDHDR]

@Win2kPro
Thank you for that. Aluminium foil is better than nothing though.

@Etaf
Thanks for the video. The heatsink seems to be able to fit in all four directions. The heatsink is also very symmetrical so I don't think it matters which way round it goes.

I guess the next step is to find some thermal paste. As another test, I felt the temperature at the area of the motherboard directly behind the CPU and I was amazed at how hot it was. It was almost so hot that I couldn't keep my finger on the area in question.

I then felt the same area of my other computer's motherboard with a similar CPU and it felt lukewarm. This seems to reinforce the theory that the problem is CPU heat not moving into the heatsink. I guess I will try find some thermal paste and tell you what happened. I do remember reading somewhere that too much thermal paste is bad. The same place also said that you should be careful when using thermal paste with silver in it.

[avarice]

an aluminum foil might make it worse.
you ought have maximum contact surface between the sink and the processor. using a foil might make both the surface rugged thereby reducing the chances of heat dissipation.

your problem can be easily solved by using a better aftermarket cooler.
i'd suggest that you remove the aluminum foil and use a thermal compound instead.
It is true that too much thermal paste is bad. u have to apply only a thin layer so that it covers all the minuscule grains between the processor and the sink that hinders heat dissipation.

and all stock cpu coolers have their fans configured so that air is taken inside towards the sink. Why? because its a better option with the smaller size of the stock sink.

[avarice]

have a look at the fan speed in the bios. it could be the issue as well. typical fan speeds are 1500rpm-2500rpm.
anything below 1000 can lead to rising temps.
cpu fans use a pwm signal to control the fan speeds according to the temperature of the cpu. there are possibilities that it could be messed up. set it to 100%. it might fix the issue if it was owing to a slower fan.

[XJDHDR]

@BruinBeer
Thank you for the links. I have just placed an order for the thermal grease. It should be here within a week and I can then provide an update on my situation.

@Avarice
I think we have already established that I should replace the foil with thermal grease. In my first post, I noted that the PC will turn itself off due to heat without the foil whereas this doesn't happen when the foil is there. Hence, I would say that foil improved my situation.

My fan spins at 2500rpm according to the BIOS. I also figured out that the heat wasn't moving from the CPU to the heatsink. That getss rid of the faulty thermometer theory and I imagine that the CPU fan is spinning as fast as it can. I didn't see any options to control fan speed either.

I would rather try thermal grease before I try an after-market cooler. My CPU is running at stock speeds so I would imagine that the stock cooler should be able to keep up. Besides, which would I rather try buying first: a R50 thermal grease solution or a R400 after-market cooler.

[avarice]

Originally Posted by XJDHDR

@Avarice
I think we have already established that I should replace the foil with thermal grease.

din quite read the other posts.. :-)
good luck with your new thermal compound.

[win2kpro]

If you are going to look for thermal compounds in my opinion these two are the best.

http://www.frozencpu.com/cat/l3/g8/c...nds-Page1.html

http://www.frozencpu.com/cat/l3/g8/c...ver-Page1.html

I believe that Innovation Cooling is better than Arctic Silver 5, but will only make a difference of 3-4° lower than Arctic Silver 5.

In the Innovation Cooling compounds the only difference in 24 carat and 7 carat is the amount in the dispenser.

With either of these compounds clean the bottom of the heatsink and the top of the processor with high purity 91% or better, or denatured alcohol. Make sure the contact areas are dry before applying either compound. If you use Innovation Cooling compound, since it is thicker in consistency that Arctic Silver 5 it may be necessary to warm the compound before application.

With either compound put an amount about the size of two bb's (.5g) right in the center of the processor heatsink. It is not necessary to spread either compound since the clamping action of the heatsink cooler to the processor will do all the spreading necessary.

You may be able to find the standard Intel compound TC-1996 which is a pre-loaded syringe with the proper amount of thermal compound for one application. If you happen to find the Intel pre-loaded applicator just use all the contents of the syringe in the center of the processor heatspreader and clamp down the heatsink cooler. Of course with the Intel compound the same cleaning method for the heatsink and processor applies.

[XJDHDR]

@Win2k
Thank you for the links. I will bookmark those pages. However, since I haven't overclocked the CPU, I would imagine that using that thermal grease would be overkill. Also, there is the cost of getting this to me in South Africa. If I am willing to wait a month for delivery, shipping costs alone will cost $15, 3x more than some standard thermal grease which I can get from one of BruinBeer's links above. I will consider if standard grease doesn't work.

[win2kpro]

With you being in South Africa I really didn't post the links expecting you to order from the site. The links, and the note about the Intel thermal compound were only posted as references to good brands of thermal compound.