Fujitsu Amilo L1300 Laptop

I have a customer with the above Laptop, which was constantly switching on and off, when I looked at it , when you connected power to it , it just made a buzzing noise, and would not come on or boot up, plus the power supply tip was getting hot.
I removed the 3 springloaded screws for the processor, and found no thermal compound present.
trying now to pinpoint what could be wrong.
Also found forums on the internet that report that this particular Laptop, suffers from overheating problems , and problems with the DC jack.
I did put Thermal compound where it was needed, but this made no difference.