LG V9120QW1M, Service Manual

Page: 14 / 116

3-3
ELECTRICAL ADJUSTMENT PROCEDURES
1. Servo Adjustment
1) PG Adjustment
• Test Equipment
• Adjustment And Specification
a) OSCILLOSCOPE
b) NTSC MODEL : NTSC SP TEST TAPE
C) PAL MODEL : PAL SP TEST TAPE
MODE
PLAY
• Adjustment Procedure
a) Insert the SP Test Tape and play.
Note - Adjust the distance of X, pressing the Tr) or Tracking(-) when the “ATR” is blink after the
SP Test Tape is inserted.
b) Connect the CH1 of the oscilloscope to the H/SW(TP) and CH2 to the Video Out for the VCR.
c) Trigger the mixed Combo Video Signal of CH2 to the CH1 H/SW(TP), and then check the distance (time
difference), which is from the selected A(B) Head point of the H/SW(TP) signal to the starting point of
the vertical synchronized signal, to 6.5H ± 0.5H (412µs, 1H=63µs).
• PG Adjustment Method
a-1) Payback the SP standard tape
b-2) Press the “OK” key on the Remote controller and the “PLAY” key on the Front Panel the same time
for more than 5seconds, then it goes in to Tracking initial mode.
c-3) Repeat the above step(No.b-2), then it finishes the PG adjusting automatically.
d-4) Stop the playback, then it goes out to PG adjusting mode after mony the PG data.
• CONNECTION
• WAVEFORM
V.Out
H/SW(TP)
R/C TRK JIG KEY 6.5 ± 0.5H
MEASUREMENT POINT ADJUSTMENT POINT SPECIFICATION
V.Out
H/SW(TP)
OSCILLOSCOPE
CH1 CH2
V.out
R/C KEY
H/SW
(TP)
H/SW
Composite
VIDEO
6.5H(416us)
VCR PART