Problem with video related system lockup II
Also Thinkpads with the ATI 9600 video chip used in T42 and T42p can cause lock-ups.
This happens after about two years of use.
Symptoms
Screen goes blank, requires hard reboot (power off-on) to get screen display. On boot may give one long, two short beeps POST code. Screen goes blank when laptop flexed, eg adjusting lid angle, squeezing around ultranav trackpad area, twisting, pressing on palmrest. POST code or screen blanking more prevalent after warm-up. Problem gets worse over time. Problem repeatable from first boot (bios) screen with tpad partially disassembled - hdd, ultrabay, extra ram, wifi removed, kb, palm reset removed, but connected.
According to http://www.technotaste.com/blog/thinkpad-t42-ati-radeon-9600-driver-and-the-blue-screen-of-death-bsod/ this problem is thermal and is caused by the GPU coming off the MB.
Solution
Replace motherboard.
Reflow the solder on the graphics chip. (remove motherboard, take it to a repair house that can reflow a ball grid array package, reassemble) - or go with the heat gun / blowtorch approach described in the above link....
