Denon DVD-1720/556 Service Manual page 20

FLOW CHART NO.11
The fluorescent display tube does not light up.
Is 3.3V voltage supplied to Pins(6,24) of IC2001?
Is the voltage of approximately -20V supplied to
Pin(15) of IC2001?
Is there 500kHz oscillation at Pin(26) of IC2001?
Are the filament voltage supplied between
Pins(1, 2) and Pins(29, 30) of the fluorescent
display tube? And the negative voltage applied
between these pins and GND?
Replace the fluorescent display tube.
FLOW CHART NO.12
The key operation is not functioning.
Are the contact point and the installation state of the key
switches (SW2101, SW2103-2108, SW2181-2183) normal?
When pressing each switches (SW2101, SW2103-2108,
SW2181-2183), do the voltage of each pin of IC2001
(shown below) increase?
SW2103, 2104, 2106, 2107, 2182: IC2001 3PIN
SW2101, 2105, 2108, 2181, 2183: IC2001 4PIN
Replace IC2001.
FLOW CHART NO.13
No operation is possible from the remote control unit.
Operation is possible from the DVD, but no
operation is possible from the remote control unit.
Is 5V voltage supplied to Pin(3) terminal of
the infrared remote control receiver (RM2001)?
Is the "L" pulse sent out Pin(1) terminal of receiver
(RM2001) when the infrared remote control is activated?
Is the "L" pulse supplied to the Pin(25) of CN1001?
Replace DVD Main CBA Unit.
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Check the EV+3.3V line and service it if defective.
No
Check the -FL (-20V) line and service it if defective.
No
Check R2002, IC2001 and their periphery, and
service it if defective.
Check D1016, D1017, T1001, and their periphery,
and service it if defective.
No
Is -14V voltage supplied to collector of Q1005?
Is the "H" signal inputted
to base of Q1016?
Check Q1015, Q1016, D1055, and
their periphery, and service it if defective.
No
Re-install the switches (SW2101, SW2103-2108,
SW2181-2183) correctly or replace the poor switch.
No
Check the switches (SW2101, SW2103-2108,
SW2181-2183) and their periphery, and service it
if detective.
No
Check EV+5V line and service it if defective.
Replace the infrared remote control receiver (RM2001)
No
or replace the remote control unit.
No
Check the line between Pin(1) terminal of receiver
(RM2001) and Pin(25) of CN1001, and service it if
defective.
20
DVD-1720/556
No
Yes
Check PWRCON
line, and service
No
it if defective.
Yes