Samsung DVD-HD850/XAA, Service Manual, Page: 82 / 94

Circuit Operating Descriptions
13-12 Samsung Electronics
(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 ZIC1 pin 169 terminal(TRD).
3) SLED LINKED SERVO
• Normal play mode
Move SLED motor slightly by means of PWM signal in ZIC1 pin 191, 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), ZIC1 uses MIRR and Global sense signal.
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 ZIC1 pin 172, 173.
Detect SYNC signal from RF in ZIC1, and output PWM signal to ZIC1 pin 189 for constant linear velocity.