Samsung DVD-A500 Service Manual page 58

(2) 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 SIC1 pin 76 terminal(TRD).
3) SLED LINKED SERVO
• Normal play mode
Move SLED motor slightly by means of PWM signal in SIC1 pin 73, 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), SIC1 uses sled FG (SIC8 pin 1, 7, 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)
Input RF signal (from Pick-up) to SIC1 pin59. Detect SYNC signal from RF in SIC1, and output PWM signal to
SIC1 pin 55 for constant linear velocity.
Samsung Electronics
Circuit Descriptions
6-13