Denon DVM-2815 Service Manual page 16

FLOW CHART NO.12
The fluorescent display tube does not light up.
Is 3.3V voltage supplied to Pin(6) and
Pin(24) of IC2001?
Is the voltage of approximately -24V to -28V
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(34, 35) of the fluorescent
display tube? And the negative voltage applied
between these pins and GND?
Replace the fluorescent display tube.
FLOW CHART NO.13
The key operation is not functioning.
Are the contact point and the installation state of the
key switches (SW2201 - 2214) normal?
Is the control voltage normally supplied to pins(38,
39, 40, 41, 42) of IC3001?
Replace IC3001.
Yes
Yes
Yes
Yes
Terminal Voltage of Pins (38 - 42) on IC3001
0.00 - 0.50
0.51 - 1.53
1.54 - 2.57
2.58 - 3.30
Yes
Yes
No
Check the P-ON+3.3V line and service it if defective.
No
Check the -FL (-28V) line and service it if defective.
No
Check R2015, IC2001 and their periphery, and
service it if defective.
Check D1016, D1017, T1001, and their periphery,
and service it if defective.
No
Is -17V 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 (SW2201 - 2214)
correctly or replace the poor switch.
38pin 39pin
KEY1 KEY2
SW2201 SW2204
POWER SKIP DOWN
SW2202 SW2205
STOP SKIP UP
SW2203 SW2206
PLAY SELECT
(KEY OFF) (KEY OFF)
No
Check the switches (SW2201 - 2214)
and their periphery, and service it if defective.
16
DVM-2815
No
Yes
Check the EV+3.3V
line, and service
No
it if defective.
Yes
IC3001
40pin 41pin
KEY3 KEY4
SW2207 SW2210
DISC-5 DISC-3
SW2208 SW2211
DISC-4 DISC-2
SW2209 SW2212
OPEN/CLOSE
DISC-1
(KEY OFF) (KEY OFF)
16
42pin
KEY5
SW2213
STILL/PAUSE
SW2214
EXTRA
CHANGE
-----
(KEY OFF)