MacBook 13 2.16GHz suddenly shuts off

Hi, thanks for your support. When I replaced the heat pipe I also removed the old thermal paste and applied a new one. Since I don't know what a good thermal paste is here are the specs of the paste I used:

Revoltec Thermal Grease (www.revoltec.com),

Thermal conductivity: >4.5 W/m*K,

Thermal impedance: <0.081 °C*in^2/W,

10% silver compound.

Would you consider this as 'good'?

Hi it is always good to help one another as i believe in paying kindness forward! Well who knows one day i might need your expertise right? Anyways, for thermal compound i usually use Arctic Silver 5. http://www.arcticsilver.com/as5.htm They are my preferred choice of thermal paste as i personally find them reliable and always keeps my chips cooler than some other branded paste i used over the years. But it is my personal preference though.

If you do happen to have a thermal gun (only if you have one / could borrow one as if im not wrong it is quite expensive), you might want to also use that to see if any part of the board is way overheated when powered on. This way you may be able to pin point the exact 'hot spot' on the board and see if there is any break in the piping. You may wish to then try and see if you can fix the area, if its the chip, check the thermal paste is evenly spreaded over the surface, or the screws around the hsf / piping is securely fastened.

All these little areas may play a part in ensuring best heat dissipation is reached. Last but not least, you may wish to add a layer of copper shim to help increase speed of heat dissipation from chip to hsf / piping. I am sure you can get these off ebay for a couple of bucks. Rmbr you still have to apply thermal paste in between the shim and cpu chip.

I do not consider myself a super techie person but above are what i would do to diagnose and try and fix a heat issue. Hope it helps and good luck!

Hi, thanks once again for trying to help me in such a kind way. Yesterday I bought a different thermal paste with a better conductivity of almost 10W/m*K. I'm afraid it didn't work as well. The macbook still shuts off. Could it be that this has something to do with the internal power supply of the CPU or GPU? Does anybody know or own a software for macbook hardware diagnosis? Apple provides such tools to their service partners but it's impossible to get it.