Well basically after about half an hour of use the laptop starts to make a luder fan noise.
After 10 minutes of this the fan goes beserk - I mean beserk and it's quite scarry. Then the entire operating system fails and the system restarts. I tried resetting the PMU but it won't reset properly. I need some other way of fixing it.
PowerBook, Mac OS X (10.5.8), 1.33 GHz PowerPC G4 Processor