Marantz NR1508 - Page 85

Check item(15). Check the I2C communication line :
Check the CPU.
Is the "I2C" waveform of the HDMI OSD [U1030] correct (like the
one shown in the diagram) when the power is turned on?
U1030
HSDA
HSCL
Check item(16). Check the I2C communication line :
Check HDMI OSD [U1030], CPU[U1013] patterns as well as soldering.
If there is no problem, go to the next step.
Remove the damping resistor [R1622/R1606]
of [U1030].
Is the "I2C" waveform correct?
The CPU [U1013] is faulty.
Replace with a new device.
Check the I2C communication line.
Recheck from check item (1).
If it does not work, replace the PCB.
OSD[U1030] is faulty.
Replace with a new device.
YES
*The diagram shows an example.
(Signal patterns vary depending on the
timing.)
Points for checking waveforms
- Crest value (3.3 V normally)
- Signal change
- SCL frequency (400 kHz normally )
Voltage scale：1.0V/div
Time scale：10us/div
NO
YES
YES
NO
85
Caution in
servicing
Electrical Mechanical Repair Information Updating