Question Laptop restarts randomly only when I am using it, it works fine while the laptop is in idle state

[The_Aoki_Taki]

I have a Dell Inspiron 5379 convertible laptop which is around 3.5 years old. I serviced my laptop last year (not from a Dell service center) and the CPU thermal paste of the laptop was replaced. Now my laptop started to switch off suddenly. It does not restart or switch off while the laptop is in the idle mood but it restarts ow switch off while I am working. However, I checked the temperature when the laptop got switched on after the sudden switched off. The laptop runs both Ubuntu and Windows 10 (dual boot). This error happens in both operating systems. I want to know about is, what is the reason for this random switch off/ restarts

Following is a screenshot of the temperature detailed got from Open Hardware Monitor tool

 

[The_Aoki_Taki]

PS: I haven't done any hardware upgrade within last 6 months. I have checked BIOS and there was an update for my laptop. So I downloaded it from the Dell website and installed it. But the error still occurs

 

[rgd1101]

check battery health?
are you running plug in or on battery only?

 

[The_Aoki_Taki]

check battery health?
are you running plug in or on battery only?

Battery is fine. This happens when I am using both plugged in and battery

 

[AlHuneke]

Is the fan running? Were you running something that was stressing the CPU when it shut down? When did you take the monitor snapshot--was it right after a shutdown and restart or during normal operation. It's running pretty warm and something is using a good bit of CPU. Try taking another snapshot after it's been off a while (do a complete shutdown) then let it run about 10 minutes without you starting any programs and see what it looks like.

 

[AlHuneke]

The idea is to get a look at the temps and CPU load at a time when it should be somewhat "warmed up" but with an idle load.

 

[AlHuneke]

BTW--I am not a fan of repasting. I have seen no convincing evidence it really helps much. I would welcome inputs on the issue. I've asked before, but no one has provided any data. Makes me skeptical. However, I am NOT a gamer and my activities rarely stress my CPU.