Quick update.

I opened up the 2400 which was a substantial task.

The hard disk had been upgraded at some stage in the past an was not touching its heatsink. Also the thermal paste on the CPU was non existent.

I removed the hard drive(for a quieter machine) and applied some new thermal paste onto the heatsink.

I am running the system via a pcmcia compact flash card.

So far so good. No crashing or screen flickering.

Thanks for the pointers.