|118 degrees C !|
Your cpu may already be damaged !
"The thermal compound between CPU & Heatsink might have baked and lost thermal conductivity."
I have encountered many cpu installations where the thermal compound had hardened, but that DID NOT affect the thermal properties significantly.
If the heat sink is not loose on the CPU when you unclamp the heat sink, don't mess with it !
"i already have changed the fan and also did the cleaning job.."
The CPU fan must be suitable for the CPU - be able to move enough air to cool it properly. If the original fan came in a boxed set with the cpu, it's adequate - if it didn't, it may NOT be !
The CPU fan MUST blow TOWARDS the heat sink ! You should see the entire fan blade from the top when it's installed the right way, no support rib(s) ontop or non moving part in the center.
The new cpu fan must be able to move at least much air as the old fan, if the old fan was adequate when it worked ok - if it's the same physical size, the ma or wattage rating should be the same as the old one or higher.
If you removed the heat sink from the CPU...
- the heat sink MUST be installed such that it's flat ontop of the cpu.
On a desktop computer, it's difficult to see well enough at the bottom of the heat sink to determine that when the mboard is inside the case.
- you MUST use one of a thermal pad, thermal compound, or thermal grease between the heat sink and the cpu. You scrape off the old thermal pad or thermal grease or thermal compound before installing new of any of those, although you can re-use thermal grease if it's clean. Thermal grease - pure silicon compound, whitish, translucent, almost clear when in a thin layer - never hardens.