External display not detected

[Notanfbiplant]

Hello. I just got an HP 21kd monitor as a second display for my MacBook Air (2015). I was told at Best Buy that I would just need an adaptor, but it would work fine. I purchased a VGA to Mini DisplayPort adapter which did not work, and I purchased a VGA to USB adapter which also did not work. It is not detecting the monitor and the monitor is not detecting any input.

I have updated OS. I have rebooted the NVRAM and SMC. I have tried to change the display setting while in Safe Mode. I truly have no clue what to do.

when I plug in the monitor to any of the adapters, it lights up but just says there’s no input.

can anyone help?

 

[mgmcc]

I purchased a VGA to Mini DisplayPort adapter which did not work

Not quite sure how you are connecting. Are you plugging the adapter into the MacBook's Thunderbolt port (Mini Display Port) and then using a VGA cable from that to the monitor?

 

[Notanfbiplant]

Yes

 

[Cory Cooper]

Hello and welcome.

Sounds like you have done the correct troubleshooting.

-Do you have another computer you can connect the HP display to?
-Have you tried resetting the HP display to factory defaults?
-What brand/model is the Mini Display Port to VGA adapter?

C