I have a computer monitor connected to 2 PC’s: 1 via direct DP, 1 via HDMI through a receiver (receiver allows for display sharing between PC #2, Apple TV, DVD player).

I noticed that the display is sometimes going black for several seconds and the comes back. It’s happened a few times now. Recently, the config has mostly been in the PC2 HDMI mode and so this is when it has happened - not sure if this is related or coincidence.

Any ideas on how to troubleshoot and determine which component has the problem - PC2, Receiver, Display? Then I can test and proactively shop for a replacement. Assuming this is something that is failing and I can’t fix it.

Have you swapped the monitors? the cable?

Not yet. The problem is that I’ve only seen the issue a few times over the past week. So, if I change something and I don’t see the problem may not mean the problem is gone unless I sit in front the monitor a lot.

But that is perhaps interesting - maybe I can set up the security cam to monitor the monitor. It should detect the monitor going black and coming back again……

It is probably not a bug but a "feature." I suspect that the monitor thinks there is a live display on the non-active port, and is trying to be smart about which to display, after a couple of minutes of "thinking" it reverts to its original setting.

It may be that a device connected to the non-active port is testing from time-to-time to see if a monitor is actually connected, and this initiates the reset sequence. It could also be that the monitor manufacturer has programmed the box to check all inputs periodically, or perhaps after some idle period. Or it could be that a cable is picking up enough crosstalk to energize a signal wire that triggers a rescan.

I am not confident, short of separating these functions, e.g. onto a second monitor that you will be able to "cure" this feature. My cynical mind asks why a monitor vendor would engineer a device that allows multiple simultaneous inputs when it is far better from their PoV to sell an additional unit.