Denon AVR-X2300W Service Manual page 86

Checking the reset waveform (HDMI Rx)
Check item(10). Checking the reset waveform :
Check the waveform.
Is the "RESET" waveform of the TP near the HDMI Rx
U1003) correct (like the one shown in the diagram) when the
power is turned on?
HDMI Rx1 HDMI Rx2
(When checking HDMI inputs 1, (When checking HDMI inputs 4,
2, and 3) 5, 6, and 7)
RESET
YES
Check the I2C communication line. (HDMI Rx)
YES
Check item(11). Check the I2C communication line :
Check the CPU.
Is the "I2C" waveform of the TP near the HDMI Rx (U1000)
correct (like the one shown in the diagram) when the power is
turned on?
*The diagram shows an example.
HSCL HDSA (Signal patterns vary depending on the
timing.)
Points for checking waveforms
- Crest value (3.3 V normally)
- Signal change
- SCL frequency (400 kHz normally )
YES
HDMI Rx (U1000 or U1003) is faulty.
Replace with a new device.
YES
Recheck from check item (3).
If it does not work, replace the PCB.
(U1000 or
Examples of confirmation waveform
NO
Check the reset circuit between
CPU (U1018) and HDMI Rx
or U1003).
If there is no problem, the HDMI
RESET
Rx (U1000 or U1003) is faulty.
Replace with a new device.
Recheck from check item
If it does not work, replace the
PCB.
NO
Check item(12). Check the I2C com-
munication line :
Check HDMI Rx (U1000 or U1003),
HDMI Tx (U1039) and CPU (U1018)
patterns as well as soldering.
If there is no problem, go to the next
step.
Checking the HDMI Rx1.
Remove the damping resistor
(R1061/R1062) of (U1000).
Is the "I2C" waveform correct?
YES
HDMI Rx1(U1000) is HDMI Rx2(U1003) is
faulty. faulty.
Replace with a new Replace with a new
(U1000
device. device.
(3). Recheck from check item (3).
If it does not work, replace the PCB.
86
NO NO
Checking the HDMI Tx.
Checking the HDMI Rx2.
Remove the damping resistor
Remove the damping resistor
(R1882/R1883) of (U1039).
(R1169/R1170) of (U1003).
Is the "I2C" waveform correct?
Is the "I2C" waveform correct?
YES YES
HDMI Tx(U1039) is
faulty.
Replace with a new
device.
NO
CPU(U1018) is faulty.
Replace with a new
device.