No input video signal detected

I am taking input from computer1 and displaying on computer2 via HDMI. First day it worked fine but now it is giving lookup error " LookupError: _video._capture initialization failed [1]: No incoming video signal detected"
My connections are all correct and I’ve tried loading the image again and resetting the board
Nothing seems to work
Please someone guide

I’m not sure I can suggest anything other than to try check all your connections again and that your HDMI source is actually outputting the correct signal.
If it still isn’t working, you could try re-image your SD card in the unlikely event that something has gone wrong with it.


Thanks for your valuable suggestion
The problem was finally resolved

Good to hear you resolved it. Could you explain what was wrong as it may help someone else who has this problem?