So I decided to check my new HDMI cable with my monitor before assembling my PC again.
I initially plugged in the cable and attached it to the monitor, but it gave a 'no cable connected' message, so I pulled out an old VGA adaptor and using that, opened the monitor menu and enabled HDMI auto switch, then removed the VGA cable.
Then I used windows update to install the detected driver. All was good until the install completed; I decided to turn off the monitor and turn it back on, and now everytime I do this, or change resolution, it gives some variance on the attached picture, which either goes away on its own in a few seconds or is removed using a change of resolution again or by switching the monitor on or off.
I've reverted to VGA and there is no issue, either when changing resolution or switching the monitor on or off.
Could someone please help me resolve this issue?
Do I have a bad HDMI cable/HDMI connector in the monitor or laptop? Is it a power issue?