After perfect install, display issues at login & other strange issues, 21.1 Mate

[geekomatic]

Rather than reinvent the wheel, I'll post my issues link from the Mint forums. Really hoping to solve this asap as medical issues are also looming.
Basically, everything went perfectly until launching firewall froze things. I didn't bother worrying and took the tower back to the owner where it then wouldn't do a thing after login (just a mess of a display and nothing to do but a hard shutdown). It did the very same from the install USB!

Took the tower back here, hooked it up, & it started right up! However, after I left it running for a while and returned, only the arrow on a black screen greeted me. Again, hard shutdown time. All system reports say things are good.

I'm currently recreating another install USB on a different thumb drive using unetbootin.

Ideas?

 

[KGIII]

using unetbootin.

I would not recommend that. There have been all sorts of problems with it over the past couple of years.

These days, I'd use BalenaEtcher.

 

[geekomatic]

I would not recommend that. There have been all sorts of problems with it over the past couple of years.

These days, I'd use BalenaEtcher.

That's odd-- I use it a lot and don't have issues unless the flash drive has issues. At any rate, the solution (in this case) was the onboard graphics causing the grief. I ended up using an old graphics card and that fixed it.