HP Zbook G8 keeps shutting down unexpectedly and restarting

[greywolfiee]

So recently my laptop has started to shut down unexpectedly usually the laptop works fine when it is first booted but after about 30 mins of using it unexpectedly shuts down, then it restarts by itself but shuts down again if I leave it idle. I have done all hardware tests from the bios, I have done HP diagnostic test as well and all was fine. I have reset my pc to factory settings as well but the issue still remains. Can anyone please advise on how to fix this issue as the laptop is completely unusable.

[banhien]

@greywolfiee 

Most likely due to heat. Please clear vent and air pathway first.

Regards.

[greywolfiee]

I did open the backlid and there wasn't much dust, I have only used this laptop for about 1.5 years and haven't used it extensively. Still I cleaned whatever dust there was accumulated on the backlid vents and the heat pipes. But the problem is still unresolved. Something, I forgot to mention in the original post was that in the event viewer, when it shuts down unexpectedly it display two error codes which are 7000 and 7009. Don't know if this helps or not, but looking forward to any help and suggestions.