- Monitor suddenly turns off but cpu still running
- No signal on monitor but cpu running - Guide
- No display on monitor but cpu running ✓ - Hardware Forum
- CPU starts but monitor display no signal ✓ - CPU & Desktop Forum
- Cpu fan is running but no display on monitor - CPU & Desktop Forum
- No display in monitor ✓ - Hardware Forum
Well, considering HDMI is not a standard, there is no single fix! The reason some fixes work for others and not you, is because their exact hardware is not the same as yours! IF it used to work, now it doesn't recover your PC back to a point when it did work. Or, look at installed updates, and if any of the updates involve DISPLAY drivers, remove them ONE at a time, and see if it helps!