Denon DRA-800H Service Manual page 63

TROUBLE SHOOTING
1. POWER
1.1. The unit does not power on
The unit does not power on
Does the power indicator on the front panel flash
in green or white when the power is turned on?
YES NO
YES
Is a fuse blown? See "1.2. Fuse is
NO
Is DC 5.2V being supplied from the SMPS PCB
[BN601] to the DIGITAL PCB?
YES
Check the circuits around the Microprocessor
on the DIGITAL PCB and replace any faulty
parts.
Does the power display on the front panel lights
green or white after approximately 8 seconds?
NO
YES
Is the fuse functioning properly? See
NO
Check the voltage of [CN753 : 9pin] on the DIGITAL
PCB while the power display is flashing in green or
white.
≧ 0.6V
Remove the connector [BN502] of the MAIN PCB.
Check the "3-2. Protection History Display Mode"
blown" TO "5. SMPS"
NO
Is DC5.2V output even when the Board in wire
[BN601] supplying power from the SMPS PCB to
the DIGITAL PCB is removed?
YES
Check for breakages and short circuits in the
circuits and parts between [CN741] on the
DIGITAL PCB and the microprocessor power
supply and replace any faulty parts.
YES
Are there any parts not fully connected into the
connectors that connect the PCBs?
"1.2. Fuse is blown" Connect the connectors correctly.
0V
Check the circuits around the Microprocessor on
the DIGITAL PCB and replace any faulty parts.
1.2. Fuse is blown
Check for leaks and short circuits
in the parts on the primary side.
Replace any faulty parts.
NO
NO
TO "3-2. Protection History
Display Mode"
YES
3.3V
Check the voltage of [CN753 : 6pin] on the DIGITAL
PCB while the power display is flashing in green or
white.
0V
63
Blown fuse
Check for short circuits between the
Check the rectifier diode in the
regulator output terminal and GND
rectifier circuit on the secondary
in the power supply stabilization
side, and check for short circuits.
circuit. Replace faulty parts if there
Replace any faulty parts.
is a short circuit.
Replace the fuse after repair.