Black screen on external monitor when air playing iPad to Mac

Hello dexxxtro,

Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with an external monitor when using iPad to AirPlay to your Mac. To start, check out this information about using an external monitor with your iMac: Connect a display to your Mac - Apple Support

"Find out how many displays you can connect

You can connect one or more external displays depending on your Mac model. To find out how many external displays your Mac supports, check its technical specifications page: 

1. Choose Apple menu  > About This Mac, double-click your serial number, then press Command-C to copy it.
2. Go to the Tech Specs page, click the Search Tech Specs bar, press Command-V to enter your computer's serial number, then click Search.
3. Click the specs page for your Mac. The number of displays your Mac supports appears under Video Support or Graphics.

Mac computers with Apple silicon

On Mac computers with Apple silicon, you can connect up to 5 displays depending on the chip in your Mac. To find out which chip your Mac has, choose Apple menu  > About This Mac. 

If you're using a Mac Studio with M1 Ultra:

• You can connect up to five external displays to your Mac using the Thunderbolt 4 (USB-C) and HDMI ports on the front and back of the computer.

If you're using a Mac with M1 Max:

• On MacBook Pro, you can connect up to four external displays to your Mac using the Thunderbolt 4 (USB-C) and HDMI ports.
• On Mac Studio, you can connect up to five external displays to your Mac using the Thunderbolt 4 (USB-C) and HDMI ports on the back of the computer.

If you're using a Mac with M1 Pro:

• You can connect up to two external displays to your Mac using the Thunderbolt 4 (USB-C) and HDMI ports.

If you're using a Mac with the M1 or M2 chip:

• On MacBook Air, 13-inch MacBook Pro, iMac, and Mac mini, you can connect one external display using either of the Thunderbolt / USB 4 ports. On iMac, connect your display to either of the ports with the Thunderbolt symbol .
• On Mac mini, you can connect a second display to the HDMI port.
• Using docks or daisy-chaining devices doesn't increase the number of displays you can connect."

If you're seeing a black screen on your external monitor, try the steps here to see if they resolve the issue: If your external display isn't detected or appears blurry when connected to your Mac - Apple Support

"If your display is blank or not detected

Try these steps if you don't see an image on your display.

Check your cable or adapter

Disconnect the cable from your external display from your Mac, then reconnect it. If the cable from your external display doesn't connect to the ports on your Mac, you can use a USB-C or Thunderbolt adapter. If you're using a USB-C or Thunderbolt adapter to connect a display, the adapter must be compliant with DisplayPort Alt Mode or Thunderbolt / USB 4.

Check how many displays you can connect

If you're connecting multiple displays to your Mac, use the Tech Specs page to find out how many external displays your Mac supports.

1. Choose Apple menu  > About This Mac, double-click your serial number, then press Command-C to copy it.
2. Go to the Tech Specs page, click the Search Tech Specs bar, press Command-V to enter your computer's serial number, then click Search.
3. Click the specs page for your Mac. The number of displays your Mac supports appears under Video Support or Graphics."

We hope this helps.

Cheers!