Envy 27s Monitor only works if plugged in when Macbook starts

[SPPearce]

I use a Macbook Pro 2017, that I connect to my HP Envy 27s via a HDMI cable (and adaptor box). 

This works absolutely fine, provided that I connect the monitor before I turn the Macbook on. If I disconnect the Macbook afterwards (say to take it to a meeting), I have to fully restart the laptop in order to be able to get the screen back, else I get an error on the screen saying "Input Signal not found, check the video cable ...".

Often the Macbook recognises that the monitor is connected, it comes up on my Display Preferences (and the windows switch to where they would be on the other monitor), but it doesn't actually show up.

Restarting will fix it, until I need to restart again.

The same issue is true for the other people in my office with similar Macbooks and other Envy 27s monitors.

Thanks for any help.

[Echo_Lake]

@SPPearce
Thank you for posting on the HP Support Community.

I appreciate your efforts to try and resolve the issue. I recommend you to go monitor menu and then input control and select input as HDMI and check if it helps.

Click here to know more on Using the on-screen display (OSD) menu refer to 12 Chapter 2 Using the monitor

Hope this helps! Keep me posted for further assistance.
Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution.

[SPPearce]

Hi Echo_Lake,

That doesn't seem to make any difference, it is set to HDMI1, as it is when it works after a restart.

Any other ideas?

Thanks,

Simon

[Echo_Lake]

@SPPearce
 

Let's try these steps if the image on an external display connected to your Mac is blank or doesn't look the way you expect: Click here

Hope this helps! Keep me posted for further assistance.
Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution.