beaglebone-black - Flipbook - Page 108
BeagleBone Black
Fig. 11.3: Third Phase Serial Number and Revision Location
TVs and monitors not working. The intent is that this page will be useful in navigating some of these issues.
As others also 昀椀nd 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://www.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://www.elinux.org/Beagleboard:BeagleBoneBlack#Software_Resources
11.5.1
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 昀椀nd 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 o昀昀, but some displays do not).
11.5.2
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.
11.5.3
OUT OF SEQUENCE
Sometimes the display and the board can get confused. One way to prevent this is after everything is cabled
up and running, you can power cycle the display, with the board still running. You can also try resetting the
board and let it reboot to resync with the TV.
11.5. Trouble Shooting HDMI Issues
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