Strange symptoms - graphics card?

I am posting here because Tech Support are maxed out, and someone may have seen the same symptoms as me. I have started experiencing a strange symptom on my Windows 10 Novatech desktop PC. When I power it on it boots normally, so far as I can tell, but all that appears on my monitor is ‘No Signal Input, Check Video Cable’. I hold in the power switch to power off then after a short pause press it again, after which the PC boots into Windows normally.

The PC is then apparently fine until the next time I power down, or restart eg after a Windows update, when I have to go through the same sequence of ‘first time doesn’t work, second time does’.

There is another symptom which has only just appeared. I have a second monitor which I use only rarely, for a specific 2-screen software package. The last time was before this ‘boot twice’ problem started. I connected it recently to the VGA port on the desktop PC as usual. Although the PC was displaying normally on my main monitor, the second monitor reported no contact with the PC and the PC did not detect the monitor. The monitor itself is fine when connected to my laptop (using the same VGA cable), so the problem seems to lie in the VGA signal from the PC.

This may be a coincidence, but the two problems together make me suspect a possible problem with my video card. (GeForce GTX 1060 6GB). But if I was that smart I wouldn’t need to ask for advice! Any suggestions?

Hi

To start with can you confirm your system stock code or serial number so i can see the full hardware setup involved.

You main monitor is connected to the Nvidia Card, can you confirm connection type.
Your secondary monitor is not connected to the system all the time correct, only when you want to use it. You are saying this is connected to the VGA port. Is this VGA port on the Nvidia GPU or VGA Port on the motherboard IO.