# Laptop freezes every time short after start up



## roger10 (Sep 9, 2007)

I have a toshiba satellite a45-s250 laptop running windows xp. I bought it in May 2004.

A while ago I bent a pin of my cpu when I tried to clean the laptop from dust. 
Eventually after about 6 month later I replaced the cpu with the same one.

*It seemed to work but kept freezing 1 min after startup.*
I completely reinstalled the system. Still the same problem.

I reinstalled about three times until it somehow worked. (I think one thing I tried was to update the bios)

I used it every day for about three weeks and everything was fine.

*One time I unplugged it from the power supply and let it run on batteries. Almost right away it froze again. *
I plugged it back in and it worked fine again.

*Later on I didn't use it for about a week. After that it always froze again every time, plugged in or not.*
It works in safemode but even if I disable everything and start up again it won't work.

Somehow my guess is that it has to do with either the *cmos battery and the bios* or it might be a *heat problem with the new cpu*.

Any idea?


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## kiwiguy (Aug 17, 2003)

My bet is that you have a marginal heat transfer issue, either a poorly fitted heatsink, a loose heatsink or no thermal transfer paste used after removal of the CPU.

Have to say, removal of the CPU chip is not a recommended activity for dust removal. I would never even dream of doing it just to remove dust, when a can of compressed air would be just as effective.

What type of thermal paste did you use when refitting the CPU to the heatsink?.


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## roger10 (Sep 9, 2007)

You're right. I wouldn't take out the cpu to dust it off.
The heatsink had collected a lot of dust in it's membrane. When I tried to take it out in order to blow out the dust, the cpu came out together because of the thermal paste.

When I inserted the new cpu I was a little impatient and didn't really research what kind of thermal paste to use. 
The one I used is called 'ceramique' by a company called arctic silver. I followed the instructions but it was the first time I ever did this, do maybe I made a mistake.

Any suggestions on what paste to use, where to buy it and how to apply it properly?

Or maybe I can use the one I have and just apply it again?

Thank you for the help!


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## kiwiguy (Aug 17, 2003)

Arctic Silver is a good product, but you also need to have started from a completely clean CPU die and heatsink, only a minimal amount of paste is needed, the heatsink and CPU die must be in perfect contact under the correct presure.

I am still uncertain how they could have "come off" during the dusting, they should have been securely clamped together, mabe that is where your problem now lies in that they are not securely clamped?


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## roger10 (Sep 9, 2007)

Thank you for the reply!

I remember, that the CPU was loose when I cleaned my laptop. There is supposed to be a buckle that locks it in place but somehow it wasn't fixed. I didn't notice and when I lifted the heatsink, the CPU came with it because of the thermal paste that worked like a glue. I had the heatsink and the CPU in my hand and was pretty surprised. When I tried to put the CPU back in, the pin bent.

You wrote that I used the right paste, so I will start one more time from the beginning by cleaning CPU and heatsink, which I did before - just maybe not enough, and I will apply new thermal paste, let's see what happens. This time I'll make sure the CPU stays in place.

Thank's again!


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## roger10 (Sep 9, 2007)

Recently I tried very hard to get my CPU properly connected to the heat sink. I think I did everything right but still the laptop freezes short after startup. 
I tried different things.
The laptop starts and runs fine in safe mode. Now the laptop has from Toshiba preinstalled a diagnostic software. It provides basic information about the laptop. I noticed that in this information model name, Part number, serial number and Bios are unknown. 
Then I installed a driver for the intel chip set and restarted. After this the laptop worked fine and diagnostic software could display the previously unknown information correctly.

It ran fine until I unpluged the laptop from it's power source. All the problems started again. I could fix it most of the time by installing the chipset driver. Sometimes it needs some recovery time from being disconnected from the power source.

Does anybody have some thoughts on this? I'm thinking it is the CMOS battery. But I have know idea how to test it or to change it.


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