dell monitor

ilona52 wrote:

I managed to solve the problem by using a different cable.

i had a mini displayport that didn't work, and now it works with thunderbolt 2 cable

does it even make sense? they look the same

Could be a bad cable. Wouldn’t be the first time. Welcome to the “fun” that is hardware compatibility and troubleshooting.

1920 by 1080 at 60 Hz is the sole supported resolution with the Dell P2319H, with DisplayPort, HDMI, and VGA connections.

Your MacBook Air 2017 supports Thunderbolt, so presumably you’re using that path either directly, or via an adapter.

What display connection path and what adapters (if any) are you using between the Mac and the display?

Are you trying to run multiple displays, or to send all output to that external display?

miniDisplayPort and Thunderbolt 2 use the same connectors. It is the wires in the cables that are different (I think the TB2 has a chip in it as well).

For Thunderbolt 3, USB-C connector is used. But USB-C connectors can be used for Thunderbolt 3, USB 3.1 gen 1 Type-C (5 gigabits/sec), as well as USB 3.1 gen 2 Type-C (10 gigabits/secon). And some USB 3.1 Type-C cables support DisplayPort.

They all look the same, but the wires and/or chips inside the cables are different.