Subject: New Build - CPU Temp Way too High?
By: Jackpine (IP: 64.229.31.*)
Written on: 18-05-2006 01:39

I am assembling a new computer for the first time. I have the following components laid out on a piece of cardboard:

Asus P5LD2 Deluxe motherboard
P4 650 3.4MHz CPU with Intel supplied heat sink and fan
Two sticks of OCZ DDR2 PC2-5400 667MHz memory (2x1024GB)
Enermax Liberty 500W PSU
MSI NX7800GTX Video Card

Everything is in the basement which is about 16C. (Cool.)

I plan on assembling this from this point on by adding components one by one to check that everything is OK, and also to learn the ropes.

I turned it on and the cpu, psu, and video card fans all operated.
In any event, I entered the BIOS (AMI BIOS, v0206) and checked the temperatures.

Motherboard 35C

Isn't the CPU temp way too high? This rig is not even under any load. Since everything is new, dust/dirt clogging up the cooling fins is not an issue.

Does anyone have any ideas if this is normal or things that I should check? (The fan came from supplied with the CPU. The heatsink had heat transfer paste already applied. I am fairly certain that the fan/heatsink assembly is fully inserted on the motherboard, but I will check.)


By: Ray (IP: 195.92.168.*)
Written on: 18-05-2006 11:28

That is way too high.

I suspect that the heatsink is not properly fixed into the motherboard. Carefully turn the motherboard-&-heatsink so that you can see underneath the board. You should see the tips of the white plastic parts of each post clearly poking through. Also, look carefully and you should see the tip of the black plastic post almost level with (but below) the tip of the white plastic post.

Two things;-
a) this heatsink fixing design is awful. It takes CONSIDERABLE pressure to fix the posts into the motherboard. But you MUST be careful doing this otherwise you can damage things
b) you say that you have everything laid out on cardboard. Not Good. Always lay things out on an anti-static mat or bag. For fixing the LGA heatsink rest the anti-static bag on firm foam or cardboard that's resting on something solid. That way, you won't destroy any components with static and you can apply appropriate pressure to fix the heatsink to the m/b. And as always, use an earth strap.

HTH, Ray
By: Ray (IP: 195.92.168.*)
Written on: 18-05-2006 13:17

To help matters, I've taken a picture of what I am talking about ...

HTH, Ray
By: Jackpine (IP: 192.75.48.*)
Written on: 18-05-2006 17:56

I will check each of the four pins to see if they are engaged on the motherboard as your photo shows.

By: Tillmann (IP: 217.224.10.*)
Written on: 25-05-2006 15:13


DO NOT USE ANTISTATIC FOIL. It is meant to protect electronic equipment while it is switched off (e.g. during transport). The foil features an electrically conductive coating, so that whatever is inside is protected by a faraday cage.

I no case antistatic foil should be in contact with powered electronic parts; short circuit may result.

Cardboard is better.

By: Ray (IP: 81.76.242.*)
Written on: 30-05-2006 02:38

Thanks for the clarification, Tillmann. That's news to me but I forgot to mention that I use the inside of an opened-out antistatic bag.

I just checked the outside of this bag and it reads 245k ohms across the printed grid. So yes, strictly speaking it's conductive but ... I read here that the definition of anti static material is that it is dissipative rather than conductive and ...

"Conductive Mats (10^1 to 10^5 ohm) have a low electrical resistance which allows ESD to flow across its surface. When attached to an earth grounding point the ESD will flow to ground and the excess charge on the mat and individual [components] will be neutralized.

Anti-Static Mats (10^5 to 10^12 ohm) have a higher electrical resistance than conductive mats. Like conductive mats they will allow ESD to flow across its surface but ... at a slower rate. This slower neutralization of ESD prevents damage to microcircuit devices which cannot tolerate a sudden flow of static charge from the device to a grounded mat.

Non-Conductive Mats (Insulator) (10^12 ohm or higher) prevent the flow of ESD across its surface. These mats are used in high voltage environments where the movement of electrical charges is not desired. In this case the movement or attraction of electricity could be life threatening.

It is important to note that an ungrounded Conductive or Anti-Static Mat will retain an ESD and transfer the charge to the next object it comes in contact with."

If I read this correctly, my antistatic bag (conductive side reading 2.5x10^5 -check my maths, please!) falls into the non-conductive category, yes?

I hears somewhere that some types of cardboard are conductive - can't remember where I read that. And it's probably the coated cardboard type - not plain cardboard, right?

Cheers, Ray
By: Jackpine (IP: 64.229.31.*)
Written on: 05-06-2006 01:08

I checked the four legs of the heatsink and found that one of them was not fully inserted. I removed the heatsink and found that the themal paste was not evenly spread over the cpu/heatsink mating areas.

As a result, I decided that I would do a cleanup and reapply the thermal paste. I removed the heat sink and cleaned off all last traces of paste. I then cleaned the cpu and heatsink surfaces with isopropyl alcohol, and reassembled using Arctic-Cooling MX-1 thermal paste. I made doubly sure that all four legs were fully inserted in the motherboard. This time the cpu temp is 35C at idle, with the motherboard at 26C. Quite an improvement!

In retrospect, I can say that my initial high cpu temperature (91C) was probably due to an incorrectly mounted heatsink, and possibly also due to poor paste "spreading."
By: Ray (IP: 81.79.70.*)
Written on: 06-06-2006 02:49

You're welcome!
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