Service manual
41
DV-NC55U/C/M
FLOW CHART NO.1
Is the supply voltage of 5V fed to pin(14) and pin
(38) of IC5001?
Check the PC 5V line.
Is the supply voltage of -19V fed to pin(27) of
IC5001?
Check the PC -19V line and Q8202.
Is there 500kHz oscillation at pin(44) of IC5001?
Check R5014-5, IC5001 and their periphery.
Check the signal lines of FIP DA, FIP CK, FIP CS
of IC5001 and IC504.
Check or replace IC5001 and IC504.
FLOW CHART NO.2
Is key switch contact and installation state normal? Replace key switch.
Is the control voltage normally into the pins(95)
and (96) of IC504?
Are the filament voltage applied between (1), (2)
and (31), (32) of the fluorescent display tube?
Also negative voltage applied between these pins
and GND.
Check the power circuit, D5004 and Q8203.
Check the fluorescent display tube and its periphery?
Check that the fluorescent display tube is free from
damages such as crack.
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
The fluorescent display tube does not light.
The key operation is disabled.
KEY-1/2
3.3V
2.5V
1.8V
0.9V
0V
KEY–2KEY–1
OFF
S5003
STOP
S5002
PLAY
Check AT 5V line.
Replace the remote control receiver.
FLOW CHART NO.3
Operation is possible from the DVD, but no
operation is possible from the infrared remote
control.
Replace the remote control receiver or replace the
remote control transmitter is necessary.
Is 5V voltage supplied to the pin(3) terminal of
remote control receiver?
Check the line between the remote control receiver
and the pin(10) of IC8201.
Is the "L" pulse sent out pin(1) terminal of receiver
when the infrared remote control is activated?
Is pulse signal supplied to the pin(10) of IC8201?
Check the line between the remote control receiver
and the pin(32) of IC504.
Replace IC504.
Replace IC8201.
Is pulse signal supplied to the pin(32) of IC504?
No
No
No
No
Yes
No
Yes
Yes
Yes
Yes
No operation is possible from the infrared remote control.
FLOW CHART NO.4
Is the signal from the pins(70) and (69) of IC504
input into the pins(1) and (28) of IC7701?
Check the LD-RVS/FWD signal line between
IC7701 and the IC504.
Check AT 8V line.
Is 8V voltage applied to the pin(8) of IC7701?
Check for mechanism and gear engagement and breakage.
No
Is FE signal inputted into the pin(150) of IC701?
Check or replace IC701.
Check the line between the IC301 and IC701.
Is loading motor drive voltage output from the
pins(9) and (10) of IC7701?
Is the loading motor drive voltage applied to the
terminal of loading motor?
Check the line between the IC702 and the
loading motor.
FLOW CHART NO.5
Does the optical pickup move up and down after
the disc is removed?(Checking of symptom.)
See FLOW CHART NO.6<The [No Disc] indication.
(In case focus servo does not function.)>
Replace IC301.
Is there input signal on the pins(52), (53), (54) and
(55) of IC301?
Is FE signal output to the pin(21) of IC301 when
the disc is set?
Check the connection of optical pickup cable.
If it is normal, replace the optical pickup.
No
No
No
No
No
Replace IC702.
No
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
The disc tray cannot be opened and closed.
The [No Disc] indication. (In case of focus error)
10. TROUBLESHOOTING
(DVD)