Question Old laptop having random shutdowns and booting-up afterwards - Reasons or solutions?

[delsrn]

I have a old LG R480-3010 Laptop from 2010.
For some reason it started to "power surge" randomly, it "shutdown/boots up" by itself, not sure how to describe. It's been happening for months now. The screen goes black for 2 seconds, and the laptop starts booting up from scratch. The power AC indicator (Green light) stays on at all times, even when the screen quickly goes dark, but the system power indicator (Red light) flickers, it turns on and off when the "surge" happens, then it proceeds with the bootup process. It also isn't a regular system restart, there's no restarting screen and the usual checks it does.

I currently run Linux on a SATA SSD, but tried putting a different Windows HDD drive, sadly the same "surge" happens in the exact same way, no crash screen or error, no matter the OS.

It can occur at any time, even when the laptop is idle or if I'm using it. Regardless of the temperature too, since I did temp checks. What is weird is that this "surge" pattern can vary - sometimes the laptop stayed on constantly for 20 days, and others where it "surged" 6x times in 4 hours. One time it couldn't even reach the login screen before "surging" and booting up again.

So far I tried: Doing memory tests (Memtest86), removing the memory and putting it on again, swapping the memory for different sticks, changing the power outlet which the laptop was connected to, wiggling the laptop AC charger cable, using a stabilizer, using a power strip, doing temperature checks, already replaced the old thermal paste before, cleaning the laptop fan and checking the insides, connecting different SSD's and one HDD (Running Linux and Windows), and even running Linux directly into a bootable pen-drive. Sadly, nothing changed. I mostly run the laptop directly via the AC charger without the battery, which seems fine since the AC power indicator is always lit green.

When I left my laptop at a PC repair shop, they couldn't diagnose or find a problem. Has anybody faced something like this?? Knows a fix?? What is causing it??

Any help is appreciated, I'm no I.T expert.

 

[Lutfij]

Welcome to the forums, newcomer!

Have you verified that the laptop isn't rebooting due to an overheating issue? You could try and replace the power brick and see if the issue persists. At which point you can narrow down the motherboard to be your issue. It's likely a power delivery area on your motherboard. If you're not well versed in locating a short or a faulty/failing component on the motherboard, you should take it to a certified laptop repair shop.

 

[delsrn]

Thanks for welcoming me and replying soon.

The thermal paste was already replaced since it was dried up, but I never saw it overheat recently.
Since this laptop is old, I saw it overheat years ago during summer. It sends a hibernate signal to the storage disk (It had a HDD originally), the screen slowly goes dark, and only then the computer stops. It takes a minute or so, unlike what's been happening now. Even when I used a HDD instead of a SSD, it didn't hibernate like before when "surging/shutting down".

I used a program to monitor CPU temperature, I think it was CPU-X for Linux, or LM-Sensors via the terminal. It didn't pass over 140°F (60°C) in the report, always between 54°C - 59°C.

I'd say that if it's because of overheating, the fan and thermometer might be broken somehow. Mostly when these random "surges/shutdowns" happened, the laptop was at a regular workload and the fan was spinning normally and quietly. I also had it "surge/shutdown" only 3 minutes after turning it on for the first time in a entire day.

I'll see if I can find another 'brick' AC charger. I just find it strange how the laptop’s AC green light seems to be always lit, as if the charger is giving enough current when plugged. Is there a simple way to test a laptop brick AC charger?
I'll also try to find a decent repair shop, since the last one didn't work out.