PC crashes during boot

[Elawen]

Good evening, I have quite a major problem. I got Ubuntu Serena (18.?) on my pc. Since today it crashes during booting, I see the grub menu, can start in recovery mode, but if I leave it, crash. If I start normal, I get to the mint logo and pc is down. It's completely turned off. Booting via installing CD brings the same result.
I ran a memory test with no errors found. A few days ago I ran some updates from level 1 to 3.
In root level I tried to repair grub but with no effect. Some packages couldn't be gained.

At some point it showed GNU grub version 2.02~beta2 36-ubuntu3.29

Any ideas what I could do? Could it also be a Hardware mistake? But if, which part possibly? Thanks for your help and sorry for the lack of further information. PC does not like me right now

[JoeFootball]

Any ideas what I could do?

Given that support for Linux Mint 18.x has ended, this could be a good opportunity to install a supported version, rather than try to resolve this one.

[Elawen]

I obey
20.1 was recommended. I'll give it a shot later since I have to download it first..
Thanks!

[JoeFootball]

I obey

You were not commanded. My suggestion is what I would do in the interest of efficiency and security. Your decision should be your own.

20.1 was recommended.

I'm sure you'll find a version and desktop of Linux Mint that works well for both your hardware and your preferences.

LM 19.x is supported until April 2023, and LM 20.x is supported until April 2025.

[Elawen]

You were not commanded.

I got that information from another side too. That's why I remarked
Somehow it went over my head that 18.1 wasn't supported anymore. My fault.

LM 19.x is supported until April 2023, and LM 20.x is supported until April 2025.

Thank you!

[Elawen]

Well well, it IS a major problem.
I downloaded 20.04, had my Live-Cd and tried to boot from it. Same result. CD checks files, everything fine, CD goes on and pfff, PC shuts off.
I'm at a loss. Could be the hard drive which would be very bad, could be anything.

Can I check via Bios whether the hard drive is down?

[JoeFootball]

... could be anything.

If it's not shutting down with a live session, it's unlikely the hard drive, but you can test that theory by disconnecting the hard drive, and trying the live session again.

I had a similar symptom once, and it was a failing power supply.

[Elawen]

I had a similar symptom once, and it was a failing power supply.

That was one of my first thoughts. Strangely, whatever else I do (searching Bios, memory check etc.) no matter how long, it works fine. Due to circumstances every shop is in lockdown so I just can't go there and let it check. I'll get some sleep and think about it