Does anyone have any ideas for addressing the problem of a laptop shutting off after a few minutes of use -- for no apparent reason? I have experienced this with a battery present and running on battery, without a battery present running on AC, and with both present.
To test the ram and hard drive, boot with the Ultimate Boot CD. It's a free download you burn to a cd (or to a usb flash drive). It contains Memtest86+ and all the manufacturer hard drive test utilities. If the laptop will run long enough to complete any of the tests, of course.
Older laptops can get a dust buildup in the fan and heatsink/heatpipe and radiator area. Requires some disassembly and cleaning, which varies from easy to difficult from model to model. If you can get the fan itself apart, use sewing machine oil on the motor shaft. Don't just add it -- add, replace and spin, remove and clean, add more several times to get all the dirt out of the shaft and bearing. If the fan keeps spinning when you give it a push, or only spins a bit and soon stops -- this is your indicator of clean or dirty.