XPS M1330

My son recently brought home a Dell M1330 XPS (Red) which he had been given by someone that had taken it apart to see how it worked, put it back together and lo and behold - it didn't any more! It came without a hard drive, so I've put an 80Gb SATA drive in it and tried booting with Hiren's bootcd;

Initially, the machine booted from the disc, but there was no display, all I got was a black screen with two white vertical lines - the dvd whirred up and then stopped and the display remained on the screen until I turned the laptop off. I tried connecting it to an external display and for some strange reason the laptop display then seemed to come to life and Hiren booted into Windows XP and sat there quite happily for some time, albeit there was no feed to the external monitor. I removed the external monitor plug and rebooted and went back to the black screen with two vertical lines, rebooted (again with the external display plugged in) - black screen and white lines again (clearly a fluke and a bit of luck before).

I removed the display and found that the previous owner had crimped one of the display leads in the hinge - re-siting this removed the display problems, however, I now seem to have another problem that I can't resolve.

I booted into the BIOS and was just checking through that when the laptop shut down - I tried a few times and it did it every time - I tried booting Hiren again using both options - the WinXP mini machine and also the Hiren DOS-based menu and again, the machine shut down after around 30 seconds.

I'm now struggling to understand why the machine constantly seems to shut down after around 30 seconds when it seemed to be ok before the display worked - it could be I've dislodged something somewhere, but I really don't know what!

Any help greatfully received...

GaryW