Cannot recover signal from PC if monitors had been turned off and on

I don't know how to phrase the issue I'm experiencing so I'll break it down into steps. I started experiencing this issue after formatting and reinstalling windows 7, all windows updates have been applied.

1. Both monitors turned on.
2. Turn PC on.
3. Everything working fine.
4. Turn both monitors off.
5. Turn both monitors back on.
6. No signal to monitors (I know the PC is working fine as file transfers had been completed)
7. Even if I move mouse around press keyboard keys PC still doesn't send signal to monitors.
8. Hard Reset PC (by pressing the reset button), everything is working again.

I've checked for;

• Windows power options
• Loose cables.
• Re-seat graphics card
• Re-seat ram
• Nvidia Driver update / reinstall.

I can leave the monitors on for hours and everything is fine but when I turn them both off and then on, the PC stops sending signal to the monitors.

I may have resolved the issue.

I swapped the monitors around....