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Sounds like it is overheating. You need ACPI to work and your fan to turn on, if that's the case.
Look under /proc/acpi/ to see if you have a directory called thermal_zone (or similar), fan, etc.
Also look for your laptop at
LQ's HCL,
TuxMobil and
Linux on Laptops. You might find the experience of others to be helpful.
And as the Rules you agreed to say, don't post the same question in more than one forum.