I've had a look through some similar threads and tried suggested solutions, to no avail.
I have a display port and HMDI port on my Inspiron, I have a monitor attached to each. For no apparent reason, the HMDI port stopped working yesterday (was working when previously shut down, was not working on start up).
It's not the cable or monitor (swapped around to check they were working), I've updated the drivers, there have been no other updates to the laptop for over a week, tried resetting the monitor. Nothing worked.
The only other thing I noticed when I started up yesterday was change to the display settings. I normally have the settings as "Extended" (with power settings such that I can close the laptop and use the monitors alone, as "1" and "2"), when I started up yesterday the display settings were "Duplicate" and the one monitor that would work was basically mirroring the laptop screen.
Any further advice...?
Thanks for posting. Apologies that your system is not performing as expected.
Here is information you may find helpful:
If you still require assistance and the system is under warranty, you may contact me privately. Be sure to include your personal information (name, address, telephone, email) and your computer's service tag number in your message. Thanks.
If there is no warranty, then you could contact our Out of Warranty team to get a quote for a paid service request.
Were you able to do a systems diagnostics to check for a hardware issue? Please run Dell SupportAssist paying particular attention to the video tests. Make a note of any error messages encountered and post back. If there are none, then this may be a software or driver issue.