Marantz NR1200 Service Manual page 97

When the results of check item (3-9.3.) are "03"
(Detection of HPD is OK / Detection of RXSENSE is OK )
Checking the EDID register. (Monitor)
Check item(3-9.4.). 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 Termit.exe.
Are the first eight bytes of the returned value "00FFFFFFFFFFFF00"?
YES
Check item(3-9.5.). Checking the TMDS :
Check the TMDS waveform at the following test
point.
N1018
HDMI
[OUT]
YES NO
Check for a short circuit in the TMDS line.
If there is no problem, the HDMI Rx/Tx
(U1027) is faulty.
Replace with a new device.
HDMI Rx/Tx [U1027] is faulty.
Replace with a new device.
Recheck from check item (3.3.).
If it does not work, replace the PCB.
NO
Check item(3-9.6.). Check communication with
the monitor :
Are waveforms of "DDCSCK" and "DDCSDA"
observed at the test point near the HDMI output
terminal [N1018]?
N1018
HDMI
[OUT]
DDCSCK
DDCSDA
YES NO
HDMI Rx/Tx [U1027] is faulty.
Replace with a new device.
HDMI Rx/Tx [U1027] is faulty.
Replace with a new device.
Example
m_1
The first eight bytes are normally
"00FFFFFFFFFFFF00".
*If the AVR and the TV are not con-
nected via HDMI, the correct register
value cannot be verified.
less than 100KHz
5V
5V
This diagram shows an example of the DDC commu-
nication 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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