Question my laptop shuts down in any tense graphical processing

[ErfanEmami]

Hi
my laptop was overheating more than often so i had to open it up and clean it and change its thermal paste but after i did them it took to much time to boot so i had to shut it down during the boot several times and I could solve it by removing my HDD in its caddy and just boot it with the SSD(where the windows was) installed (first problem) .
after that when i started playing games I realized that the heat problem kind of solved and my laptop was cooler than before but it suddenly shut down (after 40mins of playing) and at the time that I am typing , it wont last even during the intro of the games . (second problem, main)
I have installed FurMark and I tested my laptop's CPU in full load and it didn't shut down but when I test the GPU even in 720mode it wont last and the temperature rises to 99 degrees celsius and shuts down.
can anyone help me???
system cooling policy is on passive mode (no effect)
laptop : ASUS N551ZU
CPU : AMD FX-7600P
GPU : R7+R9 M280X 4GB

 

[ChumP]

It seems like you either did not apply the thermal paste correctly on yhe GPU or the heatsink is not tightened properly making improper contact wiyh the GPU die.

I'd recommend opening the laptop again and reapply thermal paste... also make sure that you tighten the heatsink correctly(tighten screws in cross pattern).

 

[ErfanEmami]

It seems like you either did not apply the thermal paste correctly on yhe GPU or the heatsink is not tightened properly making improper contact wiyh the GPU die.

I'd recommend opening the laptop again and reapply thermal paste... also make sure that you tighten the heatsink correctly(tighten screws in cross pattern).

well i did all of them 2 times but nothing changed . is it possible that the GPU is damaged ?