Samsung DVD-808K Service Manual page 91

Circuit Descriptions
(2) For CD, VCD
Receive the signal output through E, F of Pick-up, from RIC1, differently from DVD and make the tracking
error signal through RIC1 pin21. The tracking error signal is similar to DVD.
• SEARCH Mode :
Search mode : Fine seek,(Moving the tracking actuator slightly little below 255 track) and coarse search, moving
much in use of sled motor. The coarse search will be described in sled linked servo and now, the fine seek is
explained shortly.
If the object lens is located near target, cut off the tracking loop and give the control signal as many as desired
count to move the tracking actuator via SIC7 pin 49 terminal(TRO).
3) SLED LINKED SERVO
• Normal play mode
Move SLED motor slightly by means of PWM signal in SIC7 pin 54, as the tracking actuator moves along with
track during play. Control to move the entire Pick-up as the tracking actuator moves.
• Coarse serach mode
In case of long-distance search(such as chapter serach), pin 48 uses sled FG (SIC2 pin 19, which is generated) by
rotation of sled motor via hall PCB. Then, read ID and compute the existing track count after input of next
track. If the existing track count is within fine seek range, tracking begins using fine seek.
4) CLV SERVO(DISC MOTOR CONTROL SERVO)
• For DVD mode
Input RF signal (from Pick-up) to DIC1 pin50. Detect SYNC signal from RF in DIC1, and output PWM signal to
DIC1 pin 54 for constant linear velocity.
• For DC, VCD mode
Input RF signal (from Pick-up) to SIC7 pin 36, Detect SYNC signal from RF in SIC7, and output PWM signal to
SIC7 pin 55 for constant linear velocity.
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Samsung Electronics