I had this issue with a Samsung SD850 32”, would be fine for a long time then start up again with the no-signal screen after turning monitor on (after previously turning it off while the system was still on). It usually happened after a windows update. The only way to get the screen back was to reboot. The other day I applied a screen saver out of nowhere, thought my kids would like watching it. Well, it turns out the screen saver continues to run - sending video output to the monitor - even when its off! Now, whenever I turn on my screen, the saver is faithfully running and I’ve had no issues since. Its almost like powering off the monitor causes the GPU to stop providing output all together and it won’t trigger back on. I have 2 different GPUs right now (calibration reasons) and could sometimes get around the issue by switching video outputs to the other card. Once the system realized a monitor was connected, I could occasionally switch back to the original GPU. Running a screen saver and powering off...