I have had on and off past issues with my monitor not posting. Has no signal. Then one day on boot up my keyboard lights flash on, but the keyboard won't work. This was on and off also. Everything else seemed fine. After lots of research, watching YouTube, ect. I tried everything I could find, with out spending $. Reseating, cleaning memory. Checking and changing cables, ect. All fans work.
This has been going on over the last year. Then my monitor stopped working all together. It was very old, 2008. After replacing it, same thing was happening. I pulled the cmos battery. Nothing changed. Replaced it. Nothing.
I got a new psu. Same thing. So, thanks with your help, I did the up grade. And nothing has changed still. So now I'm thinking it IS the GPU. The new monitor dose display it's logo and then gos into power saving mode with no signal.
Sigh😒