©2018 NEC Display Solutions, Ltd.
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59
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71
10 Troubleshooting
Problem: No video when switching to the Compute Module input
Solutions:
•
Confirm the Compute Module and Compute Module Interface board are correctly installed.
•
On the
COMPUTE MODULE
menu of the OSD, confirm that
POWER SUPPLY
is set to
ON
.
•
On the
COMPUTE MODULE
menu of the OSD, confirm that
USB BOOT MODE
is set to
DISABLE
.
Note: The Compute Module power will have to be cycled off and on after changing the boot
mode to DISABLE.
•
Confirm that a valid OS image has been written to the Compute Module.
Problem: Compute Module hangs at the rainbow screen
Solutions:
•
The imaged OS may not include support for the Compute Module model being used.
•
Confirm that the image includes the correct corresponding file:
•
bcm2708-rpi-cm.dtb
- for the Compute Module 1
•
bcm2710-rpi-cm3.dtb
- for the Compute Module 3
Confirm the Compute Problem: Screen appears gray and blacks aren’t true black.
Solution:
•
Most OS distros on the Compute Module are set to output the video range of 16 to 235
(otherwise known as “RGB limited”) by default.
•
Make sure the display settings for handling the video levels from the Compute Module match
those on the OSD settings of the display. See the “Configuring the correct HDMI video level
encoding and decoding” section for more details.
Problem: Black borders appear around the screen image
Solution:
•
Overscan needs to be disabled. Follow the previous instructions for checking the
“
disable_overscan=1
” configuration setting in the
config.txt
file.