Dell ST2420L not working on ZorinOS 16.2

Before bringing your monitor to an electronic expert, you may want to analyze the problem first.

After updates somewhere in January 2023, my desktop monitor hooked up to my laptop with ZorinOS 16.2 freshly installed on November 2022 (just 2 months after) stopped working.

I tried to hook it to the main power and still no display. But when i use the laptop screen, everything is fine except that display setting does not show a secondary display.

Thinking it was because of frequent blackouts and a defective UPS (uninterrupted power supply) unit, i was ready to bring the monitor a (Dell ST2420L) to the electronics shop to get it fixed.

I decided to unplug the monitor from main power and the laptop hoping it would recover later. Closed the laptop lid and tried to ssh from another desktop pc but i could not get through. Changed the network cable but still could not connect.

I then realized i was working on the monitor with the laptop lid closed, i remembered a setting regarding closed lid, hibernate and suspend. I quickly jumped to search about it on the internet.

There were a couple of suggestions and ways to do it – but this is what i did.

Backup the file: sudo cp /etc/systemd/logind.conf /etc/systemd/logind.conf.bak – Next, edit the file: sudo nano /etc/systemd/logind.conf

You will see this:

Navigate to the line #HandleLidSwitch=suspend and uncomment (remove the #) and replace ‘suspend’ to ‘ignore’. HandleLidSwitch=ignore – Save file and exit.

Save file and exit.

Run this on terminal:

systemctl restart systemd-logind.service

I was logged out of current session but i just logged back in.

It was good to go – monitor back in service with laptop lid closed.