Imac why no hdmi

If using an adapter, check the specifications of the adapter to learn about supported resolutions and other details. Quit the app that is playing the video, then open the app again. Information about products not manufactured by Apple, or independent websites not controlled or tested by Apple, is provided without recommendation or endorsement. Apple assumes no responsibility with regard to the selection, performance, or use of third-party websites or products.

Apple makes no representations regarding third-party website accuracy or reliability. Several users reported getting a black screen after installing the new version of macOS, even with the monitor still turned on.

The display just turns black or dark green in some cases and eventually shuts down. Other users, on the other hand, got a No Signal error message instead of the black screen. There are also some cases where the external display just blinks randomly when connected to a Mac running macOS Catalina. Pro Tip: Scan your Mac for performance issues, junk files, harmful apps, and security threats that can cause system issues or slow performance.

There is no explanation yet why the macOS Catalina update caused the HDMI to stop working, and it will probably take a while for Apple to release an update that addresses this issue.

Before you try the solutions listed below, try some of these emergency steps first to see if they work. To do this:. If the problem is caused by a minor glitch, restarting your HDMI device should do the trick. If not, try the other fixes below. You can transfer information from your HDMI device's output port to your Apple iMac using a non-native DisplayPort converter capable of translating the signal so that the iMac can understand it.

These devices can match your iMac's native resolution, reducing the risk of distortion and other problems. According to Apple Insider, the video input feature works only with devices natively designed for DisplayPort. If you want to use your Apple iMac to watch television programs and movies, you may be able to get the same functionality using a high speed Internet connection instead of an HDMI device.

As of , several providers offer standard and high-definition television content online that can replace satellite or cable television for many people.