Bit Synchronization; Signal Processing - Kenwood DP-1100 B Service Manual

V C O 17MHz

4-11. BIT SYNCHRONIZATION

Stop the disc or shut off E F M .
Bit sync is not effec- \j
tive. JJ
Check the VCO circuit. (Parts
associated w i t h Q3)

4-12. SIGNAL PROCESSING

D e f e c t i v e p r o c e s s
circuit
NO
r
Refer to the description of focus,
tracking servo.
1 4 0
D P - 1 1 0 0 B II D P - 1 1 0 0 B II
4. TROUBLESHOOTING
Turn the disc (place it in play
I mode) or apply the EFM signal.
Set to 5 V while in play m o d e .
Check IC9. Check the VCO circuit
(L1 and D5).
C21Kor CK2M
EFMI I C 8 @
0.2/<s
NO
r
Refer to the description of bit syn­
chronization.
Check the crystal oscillator, solder­
ing and IC.
E F M I
NO
r
Check the IC and the emitter follower
Refer to focus/tracking servo.
circuit.
Y E S
NO
r
Check the microprocessor
Check the reset circuit (Note 6: Check the inverter circuit. Check the
Refer to the next page.) soldering of IC6 and IC8. Check the
pull-up resistor (R96).
Check the IC and soldering.
When the microprocessor is malfunction­
ing, the symptom does not appear clear­
ly. Therefore, disconnect the SVC con­
nector (CN10), then operate manually for
easier confirmation of the symptom.
Check the IC and the emitter follower
circuit (IC9 and Q 1 4 ) .
C - E R / W
( Q ) T
Are CE, R/W signals input
(
Are the DATA and A D ­
to the Q data RAM ( d u r i n g '
DRESS signals present at
the reading of the TOC
the Q data RAM (while
signal) (pins 8 and 10 of
reading the TOC signal)?
IC14)?
NO
circuit.