Denon AVR-X3500H Service Manual page 100

YES
Check the I2C communication line. (HDMI SW1)
YES
Check item(3-2.4.). Check the I2C communication line :
Check the CPU.
Is the "I2C" waveform of the TP near the HDMI SW1 [U1003]
correct (like the one shown in the diagram) when the power is
turned on?
I2C(HSCL)
I2C(HSDA)
U1003
*The diagram shows an example.
(Signal patterns vary depending on the tim-
ing.)
Points for checking waveforms
- Crest value (3.3V normally)
- Signal change
- SCL frequency (400kHz normally)
Voltage scale : 1.0V/div
Time scale : 10us/div
YES
HDMI SW1 [U1003] is faulty.
Replace with a new device.
YES
Recheck from check item (3.1.)
If it does not work, replace the PCB.
Check the HDMI SW1.
Remove the damping resistor [R1169/R1170] of [U1003].
Is the "I2C" waveform correct?
YES
HDMI SW1 [U1003] is faulty.
Replace with a new device.
Recheck from check item (3.1.)
If it does not work, replace the PCB.
NO
Check item(3-2.5.). Check the I2C com-
munication line :
Check HDMI SW1 [U1003] patterns as
well as soldering.
If there is no problem, go to the next
step.
NO
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