Mac mini mid 2011 restarts mid way the boot progress bar

I did replace the thermal paste before installing the OS, maybe I didn’t do it correctly, I’ll try replacing it again.

When I run AHT, I get the old version (lion’s) because it loads over the internet,

When I run it I get this error:

48NS/1/40000001: Tp0c--76.574

I assume it has with a temperature but I didn’t know which sensor is triggering it.

@thepolarcat - You may have done your self in😞I would fully clean the logic board getting as much paste off the chip carrier as I’m suspecting you when heavy and got a lot onto the green substrate and the small SMD components on it. TIM can effect the resistance and capacitance of these tiny components and you also need to be careful not to knock one off.

Actuality when I cleaned off the original paste, it did cover the small SMDs around the chips, but I didn’t think it would a problem 😮. It was my first time.

I’ll work on it today and report back.

That did it, I cleaned all the gunk on top the surrounding components and it booted in the OS and istat menus showed temperatures which wasn’t doing before.

But now the real problems arose! The first time I booted after the fix the output image was glitchy and tearing up, after I restarted its not showing any image at all but I can see rendered desktop over vnc.

I’m at a loss now, I feel I almost getting it fixed but the gpu is acting up.

@thepolarcat It is a 2011, so there's a slight chance of GPU failure. The AMD 6000 series had issues where the microscopic solder bumps between the GPU die and the substrate/interposer would fail with the machine heating and cooling. This is the same issue that caused RRoD on the 360, YLoD on the PS3 and the 8600M GT failures in older Macs and some PCs. The only real fix is GPU replacement, which may not be worth it because if you put another 6000 series from another Mac it could fail again at any time.