Trouble Shooting; The Power Can Not Be Turned On; The Power Turned On, But A Sound Does Not Output Normally. (Both Channels) - Denon PMA-720AE Service Manual

TROUBLE SHOOTING

1. The power can not be turned on. (Power indication LED does not light.）
Check the insertion of the
CUP12451-2 POWER B'D.
Check the insertion of the
CUP12450 MAIN B'D
Check whether power is
being supplied to the coil
of the standby transformer
(T901).

2. The power turned on, but a sound does not output normally. (Both channels)

2.1. Set remains in standby mode.
Check each connector.
Check whether power
is being supplied to the
FUSE F901.
2.2. Power indicator LED remains flashing red and muting mode is not canceled (protection mode is set).
Flashes in cycles of 0.5 seconds
(0.25 seconds lit, 0.25 seconds off)
Check the flashes
cycle of the red LED.
Flashes in cycles of 2 seconds
(1 second lit, 1 second off)
2.3. Set operates, but then power indicator LED flashes red (protection mode is set).
Flashes in cycles of 0.5 seconds
(0.25 seconds lit, 0.25 seconds off)
Check the flashes
cycle of the red LED.
Flashes in cycles of 2 seconds
(1 second lit, 1 second off)
Power not supplied.
Broken wire in standby
transformer (T901).
Check whether power
Power supplied.
is being supplied to
the D941-946.
Power not supplied.
Broken FUSE F901.
Check whether power
Power supplied.
is being supplied to
the coil of the main
transformer.
Power not supplied.
Power supplied.
Power not supplied.
Power supplied.
Damaged power
amplifier circuit
Damaged temperature
detection circuit.
Damaged power
amplifier circuit
Switch off power at
once, and re-apply
Green LED lit
the power after the
body temperature
has fallen sufficiently.
Red LED flashes
13
Malfunction of
D941-946.
Malfunction of
IC41,IC43.
Broken wire in main
transformer.
Malfunction of
IC41,Q454,RY92.
No problems.
For proper heat dispersal,
do not install this unit in a
confined space.
Damaged temperature
detection circuit.