Sharp DV-NC55S Service Manual page 41

FLOW CHART NO.6
The [No Disc] indication. (In case focus servo does
not function.)
Is the focus control signal output from the pin(158)
of IC701?
Yes
Is the focus control signal from the pin(158) of
IC701 input into the pin(23) of IC7701?
Yes
Is the focus control drive voltage output from the
pins(17) and (18) of IC7701?
Yes
Is the focus control drive voltage applied to the
terminal of focus actuator?
Yes
Check the connection of optical pickup cable.
If it is normal, replace the traverse chassis unit.
FLOW CHART NO.7
The [No Disc] indication. (When the laser beam
does not light.)
Is the Q303(LD POWER CTL) drive output to the
pin(46) of IC301? (Checking of symptom.)
Yes
Is 5V voltage applied to the emitter of Q303?
Yes
Is approx. 2V applied to the pin(3) of the pickup
terminal? (See note.)
Yes
Check the connection of optical pickup cable.
If it is normal, replace the traverse chassis unit.
FLOW CHART NO.8
Both picture and sound do not operate normally.(1)
Set the disc on the disc tray.
Yes
Do you have done disk loading by normality?
Yes
Is the level of RF signal which is output from
pins(29), (30) of IC301, normal?
Yes
Replace the main PWB unit.
Yes
See FLOW CHART NO.9 and NO.10.
No Check the pins(10) and (11) of IC701 periphery
circuit. If it is normal, replace IC701.
No
Check the focus control signal line between
the IC7701 and IC701.
Check AT 8V line.
No
No
Is 8V voltage applied to the pin(8) of IC7701?
Yes
Check the pin(21) of IC7701 and replace IC7701.
No Check the line between the IC7701 and the focus
actuator.
No Check the line between the pin(46) of IC301 and
the base of Q303.
No
Check the A_5V line.
No Check the line between the Q303 and pickup
terminal.
Note: Since the laser diode is very susceptible to static
electricity, be careful of static electricity or electricity
leak from the measuring equipment when confirming
the voltage.
No
Check the loading switch.
No
Check for contamination of objective lens of
optical pickup.
No
Replace traverse chassis unit.
FLOW CHART NO.9
Picture do not operate normally.
Set the disc on the disc tray.
Yes
Are the video signals outputted to the pins of main
unit connector CN802, CN803?
CN803 1PIN CVBS/Y
CN802 3PIN Y/CR
CN802 5PIN C/CB
Yes
Are the video signals shown above input into
the pins of IC2001?
IC2001 2PIN CVBS
IC2001 11PIN S-Y
IC2001 4PIN S-C
Yes
Are the video signal outputted to each pins of
IC2001?
IC2001 27PIN CVBS
IC2001 18PIN S-Y
IC2001 25PIN S-C
Yes
Are the CVBS video signal shown above input
into the pin of terminal?
IC2004 1PIN CVBS
Yes
Are the video signal outputted into the pin of
terminal?
IC2004 7PIN CVBS
Yes
Are the video signals shown above input into
the pins of terminal?
IC1206 6PIN CVBS
IC1201 6PIN S-Y
IC1202 6PIN S-C
Yes
Are the video signals outputted into the pin of
terminal?
IC1206 2PIN CVBS
IC1201 2PIN S-Y
IC1202 2PIN S-C
Yes
Are the video signals shown above outputted into
the pins of output terminal?
Are the composite video signals outputted to the
VIDEO OUT terminal (J1202)?
Are the luminance signals outputted to the
S-OUT terminal (J1201)?
Are the chroma signals outputted to the
S-OUT terminal (J1201)?
No Check the main unit.
(IC601, Q201, Q202, Q203 periphery circuit.)
Check the PC 5V line.
No
Check the parts C2003, C2007, C2008 and the
lines between them.
No
Is 5V applied to the pins(1) and (28) of IC2001?
Yes
Replace IC2001.
No Check parts C2016, Q2002 periphery circuit and the
line between them.
No
Is 5V applied to the pin(6) of IC2004?
Yes
Are the DVD_H line at pin(2) of IC2004 on "L"
level?
Yes
Replace IC2004.
Check the DVD_H line.
Check the line between pin(7) of IC2004 and pin(6)
No
of IC1206.
No Check C1201, C1206, Q2003, Q2002 periphery
circuit and the lines between them.
Is 5V applied to the pin(3) of IC1201, IC1202 and
No
IC1206.
Yes
Replace IC1201, IC1202 and IC1206.
No
Check the VIDEO OUT terminal (J1202) and the
line between the pin(2) of IC1206 and the VIDEO
No OUT terminal (J1202).
Check the S-OUT terminal (J1201) and the line
No
between the pin(2) of IC1201 and the S-OUT
terminal (J1201).
Check the S-OUT terminal (J1201) and the line
between the pin(2) of IC1202 and the S-OUT
terminal (J1201).
No
No
No
No