Monitor goes off (black screen) Please help.....

Hello guys, im new at this forum. I opened this account just for this unexpected problem and i can't find the solution. I request help from you all. Any reply is appreciated.

Everything is okay with my PC, MY Rig is: i5 9600k 16gb ram gtx 1660 ti asus prime z370 P II motherboard.

But i was trying to overclock a month ago (i was just trying the limits) and i boosted the clock like from 12000mhz to 15000mhz accidentally and i opened the fans to 80% speed. Then my monitor went off. I guess it was too much for it. Then i restarted my pc, everything was ok. Then monitor started randomly to black off and fans were at high speed (same as i made that overclock) . This happens when i play, when i watch something, even when nothing is opened in pc, just desktop.
What i have tried : 1. I deleted the gpu tweak 2 application (where i overclocked my pc)
2. i installed gpu tweak again and overclocked it like in so small amount like from 12000mhz to 12010mhz.
3. i made a half format of my pc (just local disk C:)
4. i made a full format of my pc.

I tried all of these, nothing worked. And all i have in my mind is to detach the gpu at attach it again, nothing more. Please help me. I made a brand new PC with a monitor and this problem causes all by my fault and now i can't play any game that exists.

Maybe clear the CMOS?

bobkn said:

Maybe clear the CMOS?

tried that too, i did detach and attach the gpu, now it seems fine but im not sure