Laptop Broken? Tools needed!

[Mauli]

I have a laptop and recently its being acting sort of weird. with that i mean, sometimes it doesnt switch on at all, sometime it gets past the bootscreen, acceses the hd just to then stop doing that and rest showing a black screen and sometimes it just switches itself off.

I could really use some diagnostic tools to figure out if something is wrong with the hardware. I thought it could be the power supply to it, as the battery is practically dead that seemed plausible, however, that would effect hd access during the boot sequence....

I am at a complete loss here, so any help would be appreciated. Diagnostic tools would do...

Thanks for your help in advance

Mauli