Hp G61 shuts down abruptly after 3-5 minutes of usage

[smd]

I have a HP G61 laptop. It uses the AMD sempron processor. The laptop is about 2 years old and therefore out of warranty(It came with 1 year warranty). Once I switch on the laptop it works for about 3-5 minutes, then shuts off abruptly without any warning. I've tried swapping R.A.M, HDD, and removing wireless card, but the problem still persists.
What could be the problem, what components do I check? Thanks

[TBoneit]

Re: Hp G61 shuts down abruptly after 3-5 minutes of usage

check for overheating. The heatsink could need to be cleaned.

[smd]

Re: Hp G61 shuts down abruptly after 3-5 minutes of usage

I have already cleaned the heatsink and applied new Thermal interface material, but the problem persists.

[tschanuka]

Re: Hp G61 shuts down abruptly after 3-5 minutes of usage

The fan is spinning?
Try it with all components and battery removed.
Also check for dc-jack problems.

If overheating can definitely be excluded and nothing from above helps, then there are no more options than professional diagnosis and repair (service or by yourself). Could be the thermal sensor on the motherboard or something.

[Agent24]

Re: Hp G61 shuts down abruptly after 3-5 minutes of usage

Try taking the battery out?

Edit: oops, just noticed tschanuka already said that...