Weird Cpu Overheating

[Ric S]

Specs
Mobo p5gc-mx/1333 asus
4g ram
c2d e7200 stock heatsink

my cpu has been running perfectly since 3-4yrs
just a few months a go it started to heat upto 80c but would not shutdown
or show any signs of stress no matter what so, i decided to let it be.
around 3 days ago it gave an overheating message and shut down!!! O_O

What i did:
1. cleaned the heat sink
2. applied fresh paste(wasn't arctic silver for sure - but was white in color)
3. underclocked it to 1.9ghz(2.53 being stock)
after that it did startup but still heats up real quick upto 70 and sometimes upto 80 and ocasionally shuts down.

i am un able to determine any possible cause for this to happen.

pl. heip

 

[Marco Washa]

I suppos you could have one of this two problems:

1 - Case have serious airflow's problems

2 - Your cpu is going to die

I'm inclined for the second case 'cause your downclocked didn't work. Slowly current wear out transistor inside of cpu and it can't run as before. Maybe if you can undervolt it you could get it stable

 

[Ric S]

I suppos you could have one of this two problems:

1 - Case have serious airflow's problems

2 - Your cpu is going to die

I'm inclined for the second case 'cause your downclocked didn't work. Slowly current wear out transistor inside of cpu and it can't run as before. Maybe if you can undervolt it you could get it stable

i am new to hardware kind of stuff , how do i undervolt and what will be its effects??

 

[Marco Washa]

i am new to hardware kind of stuff , how do i undervolt and what will be its effects??

Undervolt is a practise doable via motherboard that is used for make cpu less hungry of current.
Is a difficult practise for a newbie and is some cases impossible to do, dependes on your motherboard/chipset if you can do it.
You have to search in your bios for current management, and remember less current you give to cpu less frequency it has