User Manual

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11.4 Trouble Shooting HDMI Issues

Many people are having issues with getting HDMI to work on their TV/Display.

Unfortunately, we do not have the resources to buy all the TVs and Monitors on the

market today nor go to Ebay and buy all of the TVs and monitors made over the last five

years to thoroughly test each and every one. We are depending on community members

to help us get these tested and information provided on how to get them to work.

One would think that if it worked on a lot of different TVs and monitors it would work on

most if not all of them, assuming they meet the specification. However, there are other

issues that could also result in these various TVs and monitors not working. The intent is

that this page will be useful in navigating some of these issues. As others also find

solutions, as long as we know about them, they will be added here as well. For access to

the most up to date troubleshooting capabilities, go to the support wiki at

http://elinux.org/Beagleboard:BeagleBoneBlack_HDMI

The early release of the Software had some issues in the HDMI driver. Be sure and use

the latest SW to take advantage of the improvements.

http://elinux.org/Beagleboard:Updating_The_Software

11.4.1 EDID

EDID is the way the board requests information from the display and determines all the

resolutions that it can support. The driver on the board will then look at these timings and

find the highest resolution that is compatible with the board and uses that resolution for the

display. For more information on EDID, you can take a look at

http://en.wikipedia.org/wiki/Extended_display_identification_data

If the board is not able to read the EDID, for whatever reason, it does not have this

information. A few possible reasons for this are:

•

Bad cable

•

Cable not plugged in all the way on both ends

•

Display not powered on. (It should still work powered off, but some displays do not).

11.4.2 DISPLAY SOURCE SELECTION

One easy thing to overlook is that you need to select the display source that matches the

port you are using on the TV. Some displays may auto select, so you may need to

disconnect the other inputs until you are sure the display works with the board.