" now it occurs even if BIOS " so Windows isn't running so the monitor is now suspect. Try another monitor.
Never had any issues until a few weeks ago when I upgraded to Windows 10. Afterward, monitor would randomly lose signal and I'd have to toggle it off and on again to make it work. The problem has gotten worse and now it loses signal immediately and PC is unusable. PC itself works fine. Here's what I've tried.
1. Updated drivers numerous times, never any improvement. I originally thought it was software issue due to W10 but now not sure.
2. Switched out Nvidia GPU and connected to on board GPU. No difference.
3. Swapped monitor connection from DVI to HDMI. No difference.
Originally it only occurred after booting to Windows but now it occurs even if BIOS so not sure it's a W10 issue. Also doesn't seem to be the monitor or GPU. Any ideas? Like I said, I thought it was W10 related but now I can't even get monitor to stay on long enough to make installing Win7 easy (constantly spam monitor on and off to see screen briefly). Hope I'm missing something obvious. Aware it could be hardware issue but odd it'd start same day I upgrade to W10.