Denon AVR-X2400H Service Manual page 112

When the results of check item (58) are "30"
(Detection of HPD is OK / Detection of RXSENSE is OK )
Checking the EDID register. (Monitor1)
Check item(59). Check the Monitor EDID :
① Unplug the AC cord. Plug the AC cord into a power outlet.
② Send the transmission command "m_1" from Termite.exe.
Are the first eight bytes of the returned value "00FFFFFFFFFFFF00"?
YES
Check item(60). Checking the TMDS :
Check the TMDS waveform at the following test
point.
N1031
HDMI HDMI
OUT 1 OUT 1
YES NO
Check for a short circuit in the TMDS line.
If there is no problem, the HDMI Tx
[U1039] is faulty.
Replace with a new device.
HDMI Tx [U1039] is faulty.
Replace with a new device.
Recheck from check item (3).
If it does not work, replace the PCB.
NO
Check item(61). Check the communication :
Are waveforms of "DDCCLK and DDCSDA" ob-
served at the test point near the HDMI output
terminal [N1031]?
N1031
HDMI HDMI
OUT 1 OUT 1
DDCSCK
DDCSDA
YES NO
Check for a short circuit in the DDC line.
If there is no problem, the HDMI Tx
[U1039] is faulty.
Replace with a new device.
HDMI Tx [U1039] is faulty.
Replace with a new device.
Example
m_1
The first eight bytes are nor-
mally "00FFFFFFFFFFFF00".
*If the AVR and the TV are not
connected via HDMI, the cor-
rect register value cannot be
verified.
less than 100KHz
5V
5V
This diagram shows an example of the DDC communica-
tion waveform.
-The high level voltage is 5V.
-The frequency of the DDC CLK is 100 KHz or less.
Check at each test point.
Voltage scale：2.0V/div
Time scale：40us/div
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