How to check HDMI faulty

1. HDMI EDID lines

If you want to check if there is any HDMI-related HW defect on N2 board, first, please check edid data lines of HDMI through sysfs.
You will have edid data like the one below, if HDMI EDID lines have no issue.

root@odroid:~# cat /sys/class/amhdmitx/amhdmitx0/rawedid 
 
(an example result)
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
root@odroid:~# cat /sys/class/amhdmitx/amhdmitx0/disp_cap
 
(an example result)
480p60hz
576p50hz
720p60hz
1080i60hz
1080p60hz
720p50hz
1080i50hz
1080p50hz

2. Check HDMI block

You can check internal HDMI block of N2 cpu using a Digital Multi-meter as following.

- Remove N2 board power first.
- Measure resistance value between “a point of part L8 (or L9)” and “GND (board ground)”.
You should have around 500kΩ ~ 1MΩ or higher value if hdmi block of your board is OK.
If hdmi block is broken, the value may be measured as several k-Ω or fewer.

N2 HDMI Connector

Don't miss the possibility that HDMI timing setup from N2 hdmi drivers doesn't match with the timing specification of your monitor.

1. Check Timing Setup

- To narrow down root causes, please set the boot slide switch to “MMC” instead of “SPI”.
- Check your monitor's hdmi timing from debug files.
You will have two debug files in vfat file system folder of your card.
1. edid.bin
2. display.bin

- Please make a post on ODROID N2 Forum with this information.
With some monitors, it's needed to adjust hdmi timings,
so, please post this information and attach two debug files on ODROID N2 Forum, then Hardkernel members will help you.
ODROID Forum N2 Issue