Denon DRA-800H Service Manual page 91

When the results of check item (3-8.1.) are "00"
(Detection of 5V is not OK)
Check the +5V voltage. (HDMI SW)
Check item(3-8.3.). Check the +5V voltage :
Does "+5V" at the following test point indicate 5 V? [JK701/JK711/JK721]
JK721 JK711 JK701
HDMI 3 HDMI 2 HDMI 1
[Blu-ray] [DVD] [CBL/SAT]
+5V +5V +5V
YES
HDMI SW [IC701] is faulty.
Replace with a new device.
Recheck from check item (3.2.).
If it does not work, replace the PCB.
NO
Check for a short circuit in the 5 V line and the 5
V Switch IC [IC733].
If there is no problem, the HDMI SW [IC701] is
faulty.
Replace with a new device.
When the results of check item (3-8.2.) are
(Detection of DDC is not OK.)
Check the DDC line. (HDMI SW)
Check item(3-8.4.). Check the DDC Line HPD line :
Are waveforms of "DDCSCK" and "DDCSDA" observed at the test point near the HDMI input terminal
[JK701/JK711/JK721]?
JK721 JK711 JK701
HDMI 3 HDMI 2
[Blu-ray] [DVD]
YES
HDMI SW [IC701] is faulty.
Replace with a new device.
Recheck from check item (3.2.).
If it does not work, replace the PCB.
91
"00 or 04"
less than 100KHz
5V
HDMI 1
[CBL/SAT]
5V
DDCSCK
DDCSDA 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
NO
Check for a short circuit in the DDC line.
If there is no problem, the HDMI SW [IC701] is
faulty.
Replace with a new device.