Denon AVR-X6400H Service Manual page 112

Check the SPI communication line. (DSP2)
YES
Check item(34). Check the SPI communication line :
Check the CPU.
Is the "SPI" waveform of the TP near the DSP [U201] correct (like
the one shown in the diagram) when the power is turned on?
CS
U201
YES NO
Check item(35). Check the SPI communication line :
Check DSP [U201], CPU [U6201] patterns as well as soldering.
If there is no problem, go to the next step.
DSP [U201] is faulty.
Replace with a new device.
Recheck from check item (1).
If it does not work, replace the PCB.
*The diagram shows an example.
(Signal patterns vary depending on the tim-
ing.)
Points for checking waveforms
- Crest value (3.3V normally)
- Signal change
Voltage scale : 2.0V/div
Time scale : 2us/div
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