ATI Mobility Radeon 9700 Problems !

Hi All,

I have a mobility Radeon 9700 in an LG LS50-8 laptop (Pentium 1.7, 1Gb
Ram)

I am a bit annoyed at the moment, because I think it may have fried
itself, after playing a game for 5 or 10 minutes. Sometimes in the
past when a playing games the system would shut itself down, which is
fine. But why would it overheat itself and not go into any sort of
shutdown/mitigation ? Is this normal.

So what happened was the screen started cycling through colours, so I
turned the computer off and wnet to reboot, now I can't get to
BIOS/POST. Screen is blank, cd spins up, hard drive light intitially
flashes, then nothing.

I assume the GPU is fried, but how can i test this vs maybe the CPU ?

Secondly. If it is the GPU where can I get a replacement ? I have
had a quick search but haven't seen any floating around yet.