Laptop a21m IBM keeps shutting down

[niggles]

I'm done! seriously, I can not figure this out. My A21M IBM laptop just shutsdown for no reason. It might last 20 minutes and the boom, it's gone. I've pulled out the CPU fan because I thought perhaps it's a temperature issue. There doesn't seem to be any temperature gages in this laptop so I don't know if it's overheating or not. Given that I don't see how it would simply shutdown. How would it know it needed to shutdown for a temperature issue if there was no thermometer right? When this first started I could keep it on up to an hour, or slightly more. I have reformatted quite a few times thinking that it might be an OS issue, but the problem keeps re-occuring. I read somewhere that there was a capacitor issue and that in order to make sure the capacitor didn't get messed up it would be necessary to pull the battery and the CMOS battery and hold the power button down for 90 seconds. Well I did that and it didn't work, it still shuts down. Does anyone have *any* insight on this problem?

 

[LiLithTecH]

Are there any CODES displayed or BEEPS when it powers up (i.e. 0175, 02F5, etc...)?

I have seen bad LCD invertors (or connections) cause this same type problem.

 

[niggles]

no, it boots fine, I've run all the IBM diagnostics and they all say that everything is fine.