I have an older desktop (2011) that are giving me headaches. I'm close to just throw the towel and dive into my pockets for a new one, but when it works it is still more than fine for my purposes so here's a try.
PhenomII 1090T 6x3,20GHz
AMD HD6970 2GB GDDR5
-During startup I see the windows 10 splashscreen and the loading wheel, but then the monitor informs me that there are no video input and it goes into sleep mode. The comp seems to be running. Sounds like its working alot for a minute or two, then ends up in what I can only describe as idle. After a few reboots it showed the blue repair startup screen. Tried repair, but it said ”Cant Repair”
-Tried "reset the PC". Got througt the black reset screen, but somewhere througt(~20%) the blue installing screen same result. No video output/idle comp.
-Tried reinstalling Win10 from an USB drive. After installation I got through the account and Wifi-setup, but then same result.
-Tried rebooting in safe mode, but i got stuck in an endless loop of "log in with your name -> create password -> answer 3 questions ->something went wrong"
-Happens it boots up into "reverting changes" and then back to idle etc.
-I removed the GPU, cleaned it and put it back in. Tried using another slot for the GPU. It booted to windows setup (choose location). Left it there for a minute or two and again idle comp etc.
-One time it seems like the CPU overheated in the idle state and it shut down. When ever i have looked the fan is runnig though.