Kenwood DP-1100 B Service Manual page 132

4.3 TRACKING SERVO
Is the RF signal present at h e n the servo is not ef-
W
pins 6 and 7 Of CN6? fective (Servo: OFF)
The tracking servo is
not effective.
4-4. Pickup feed motor circuit
1 3 6
D P - 1 1 0 0 B II D P - 1 1 0 G B II
4. TROUBLESHOOTING
When the disc has
scratches Normal waveform
T . E r r o r s i g n a l
When the servo is effec­
tive (Servo: ON)
Is the tracking error s i g n a l '
applied to the tracking
potentiometer (pin 5 of
C N D ?
N O
Check the limiter a m p , Q 2 7 , Q 2 8 ,
Q 3 0 and IC14.
Confirm by using a disc relatively
free from scratches.
C K 8 8 ( 8 8 . 2 k H z )
ICI 5 ©
5/iS
A r e t h e P L C K ( 4 . 3
Are TS1 and TS2 output
> 5 <
MHz) signal a n d CK88
normally? Is the difference
(88.2 kHz) signal input to the
in output 2 dB or less (pins
semi-custom IC (at pins 40
18 and 19 of IC15)?
and 37 of IC15)?
N O
Inverter? (IC5) Check the signal processing PCB.
I C 2 (2/2) O U T P U T W A V E F O R M
The output varies depending on the
degree of eccentricity of the motor
spindle and the disc.
Are the KGC, FOKG, and
DCON signals applied nor­
mally to the transistor and
FET?
- 1 2 V ( R 2 2 2 , 2 2 7 , 225)
N O
N O
•FOKG.... Is the RFOK signal fed to
Check the tracking error amps, I C I ,
the microprocessor?
IC2, Q 1 1 , Q 1 0 , D 1 0 and D 1 1 .
• F o r KGC a n d D C O N , r e f e r
to respective chapters.
Check the TEG1 and TEG2 c o m ­
IC15 (Servo PC board) parators. Check ICI 2 , IC13, D26
and D 2 7 .
T h e a c t u a t o r a n d t h e p a r t s
associated w i t h the pickup are
defective.
Y E S
Check IC12 (1/2) and peripheral cir­
cuit.