Hi, I was browsing the internet looking for some advice and NOTICED this forum. Maybe someone could help me.

I bought my father an emachines E520 laptop nearly 2 years ago now. It runs on vista home basic with service pack 2.

It started shutting itself down suddenly, I checked the tempreture and it was running at 79 degrees C. So I cleaned all the dust out of the fan and surrounding area, which turned out to be a nightmare of a job as there was no access to the fan from underneath and I had to go under the motherboard......a place I don't like to be if I can help it!

Anyway I removed a substantial amount of dust and fluff, turned the laptop back on and it turned it'self off after about 10 minutes.

Before I played with it, it was only turning off now and again after a few hours of use, now it is turning off after a few minutes of use.

Aaaarrgh what have I done?

Can anyone help me please?

Many Thanks If you have a fan that is on its way out it could be shutting itself down. The cooling fans in computers these days have TACH's in them that send pulses and by pulse frequency you know the speed of the fan in RPM's, if the motherboard senses a loss of this signal it will shut itself down to protect itself.

The other possibility you are facing is where the thermal COMPOUND between the CPU and the heatsink is DRIED up and no longer a good heat conductor to sink the heat away from the CPU and so the motherboard senses the CPU temp going into the critical and shutting itself down.

For this type of problem there is no easy fix. You are most likely facing replacing a fan that isnt functioning properly or removing the heatsink, removing the old heatsink compound with q-tips, and then applying new thermal compound such as arctic silver and reattaching the heatsink to create a better thermal bond.

Worst case scenario of an overheated system is microfractures in the traces internally to the CPU where the traces are connected until you reach a specific temperature at which the traces microfracture pulls away creating a gap in which electrons can not flow, and CAUSING usually a blue screen or a shutdown condition.

Wish you the best of luck diagnosing..if you have any further questions feel free to ask  =)