External HDMI suddenly not working

[Michael_Lewis]

I’ve had no monitor problems with my Librem13 until today. I pulled it out of my backpack, plugged into my external monitor and … nothing. I get a brief flash on the monitor as -it- detects something, but then it gives up and goes back into power save mode. I’m running the stock Purism OS (kernel 4.2.3purism-rc2). I’ve tried the Fn+F7 key but it doesn’t don’t do anything. ‘Detect Displays’ in the preferences panel doesn’t find it either.

Does anyone know how I can figure out if my HDMI connector broke, or if I borked some setting somehow?

Thanks,
-Michael

[mladen]

Internet is full of advices, like: https://www.lifewire.com/fix-hdmi-connection-problems-1846811. I can only suggest to try different monitor, or try another PC with the same monitor.

[mladen]

Also, Jeff noted it couldn’t hurt to test the HDMI signal:
https://www.amazon.com/Parts-Express-Cable-Signal-Tester/dp/B005WU9FNG

HDMI Signal Tester

[Michael_Lewis]

Well, thanks for the tips, but the problem was apparently either software or firmware. I booted from a USB stick (for unrelated reasons) and it suddenly started working again. Then when I rebooted into PureOS, it remained working. So its fixed, but I don’t know why.

[bingen]

I had the same problem and this trick worked for me:

HDMI Monitor Not Working Librem 15

It’s working again now. For future reference in case anyone else encounters this problem, here’s what I did: Unplugged all USB devices, the HDMI cable, and the power cable Turned off the computer Turned the computer back on Plugged back in the HDMI cable My guess is that it was the powering off of the computer (and then powering it back on) that did the trick. When changing the OS and firmware versions, I was rebooting the computer instead.

[scaled]

Anyone saw random blinks when using powerful cell phone? Blinks, which synchronized with cell phone activity. I mean blinks on internal and external screen.