Denon DRA-800H Service Manual page 83

3-5. Error Code H1-08 failure detection procedure
Checking device. [IC781 : ADSP21487KSWZ2B82]
Check the power supply voltage.
Check item(3-5.1.). Check the power supply volt-
age. :
Does the power supply voltage of the DSP [IC781]
indicate the appropriate voltage (1.1V, 3.3V)?
The test points are as follows.
C7868 C7605
IC781
1.1V
3.3V
YES
DSP [IC781] is faulty.
Replace with a new device.
Recheck from check item (3.1.).
If it does not work, replace the PCB.
NO Check item(3-5.2.). Check the power supply volt-
age. :
Check the power supply components [IC741/
IC743/Q7415] on the substrate and peripheral
pattern.
If there is no problem, remove the DSP [IC781]
from the substrate and measure the voltage at
the test point of check item (3-5.1.).
Is the voltage correct (1.1V or 3.3V)?
YES NO
The power supply circuit is faulty.
Replace the PCB.
Checking the reset waveform.
Check item(3-5.3.). Checking the reset :
Check the CPU.
Is the waveform of the TP near the DSP [IC781] correct (like the one
shown in the diagram) when the power is turned on?
D_RST
IC781
YES NO
Check the reset circuit between CPU [IC751] and DSP [IC781].
If there is no problem, the DSP [IC781] is faulty.
Replace with a new device.
Recheck from check item (3.1.).
If it does not work, replace the PCB.
83
Examples of confirmation waveform
Voltage scale：1.0V/div
Time scale：20ms/div
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