Denon AVR-X6400H Service Manual page 137

When the results of check item (89) are "22"
(Detection of DDC is OK)
Checking the TMDS status register (HDMI DDC Buffer)
Check item(92). Check the TMDS CLK detection status of the register
:
Send the following command from Termite.exe.
Send the command "i 0006 00FF 0001".
When the following value is returned, go to YES.
"F8"
When the following value is returned, go to NO.
"F0"
YES
Check item(94). Check the AUDIO signal output :
Check the AUDIO signal waveform at the following test point.
Is the waveform like the sample?
(MCK/64FS/FS/I2S0/I2S1/I2S2/I2S3/SPDIF)
U3401
YES
The DIGITAL AUDIO block is faulty.
Check the DIGITAL AUDIO device.
Check "AUDIO" in troubleshooting.
If it does not work, replace the PCB.
Recheck from check item (4).
If it does not work, replace the PCB.
Example
i 0006 00FF 0001
F8
NO
3.3V
The diagram shows an example of the wave-
form of I2S0.
Waveform check points
- Crest value (3.3 V normally)
- Signal change
Check the waveform of each pin.
Voltage scale : 1.0V/div
Time scale : 500us/div
NO
HDMI Tx [U3401] is faulty.
Replace with a new device.
Check item(93). Checking the TMDS input waveform. :
Check the TMDS waveform at the following test point.
Is the waveform like the sample?
U3401
70/71/73/74/76/77/79/80 pin
YES
HDMI Tx [U3401] is faulty.
Replace with a new device.
Recheck from check item (4).
If it does not work, replace the PCB.
137
3.3V
TMDS Signal
Example of waveform in check ①
Voltage scale : 1.0V/div
Time scale : 20ms/div
TMDS
Example of waveform in check ②
Voltage scale : 1.0V/div
Time scale : 1s/div
NO
Check for a short circuit in the TMDS line and the Front
HDMI FFC.
If there is no problem, the HDMI DDC Buffer [U5501] is
faulty.
Replace with a new device.