Windows 10: HDMI output appears inactive

I have a new HP all-in-one "desktop", added second monitor about 3 weeks ago, worked for about a week and then second monitor went blank. Called HP, they walked me thru a "fix" which worked. A week later, same thing. I did their fix and it worked a second time. Happened again this week, fix no longer works. Monitor is good, cables are good, I'm thinking the HDMI output is bad but don't know how to check. Should it show up in device manager as a separate entry under display output? or is it just part of the display output and not listed separately. I don't have another HDMI device to check the output other than the second monitor.

I have used second monitors for 20 years and this is the first time anything like this has happened. HP tech support has NOT been helpful, even tho the PC is under warranty.

:)

 

PC with Dual Displayport output with two TVs plugged in can only get Audio to output on one of the TVs?

Thank you for your input. I'd still like to figure this one out, as we may run into this on other standard PC implementations. It could be any HDMI or Displayport output device....a monitor with built in sound, etc. The Question is can you output audio
to two different devices when you have 2X Displayport or HDMI output graphics card. Windows does not appear to have an option for more then one audio output. Someone has to have run into this?!

 

Can't get sound through HDMI cable

I also cannot get sound out to the TV connected via HDMI. I see "Playback" and "Realtek Digital Output" as the only 2 choices for sound playback devices. HDMI is excluded.

Also, I now cannot get the sound to come from the external speakers directly connected to the output jack. ONLY the internal speakers appear to work.

 

It sounds like the port has gone bad. You've done the troubleshooting, so I would start asking HP for a replacement.

 

Yes, it should show up as a second monitor in Device Manager > Monitors.
When the second one is disconnected it becomes hidden but you can show that in Device Manager.
What is HPs fix ?

 

Their fix was to turn every off and disconnect, then hold power button for 15 seconds, then restart and reset the BIOS to factory defaults. Worked the first time when I was chatting with them, worked the second time on my own. Didn't work the third time. Device manager for display adapter shows the intel display adapter, device manager for monitors only shows generic pnp display which is the main display on the all-in-one.