Vcr Part; Electrical Adjustment Procedures - LG RC-185 Service Manual

ELECTRICAL ADJUSTMENT PROCEDURES

1. Servo Adjustment
1) PG Adjustment
• Test Equipment
a) OSCILLOSCOPE : PAL SP TEST TAPE
• Adjustment And Specification
MODE
PLAY
• Adjustment Procedure
a) Insert the SP Test Tape and play.
b) Connect the CH1 of the oscilloscope to the H/SW and CH2 to the "VCR VIDEO" TP for the VCR.
c) Trigger the mixed Combo Video Signal of CH2 to the CH1 H/SW, and then check the distance (time dif-
ference), which is from the selected A(B) Head point of the H/SW signal to the starting point of the ver-
tical synchronized signal, to 6.5H ± 0.5H (416µs, 1H=64µs).
• PG Adjustment Method
a-1) Playback the SP standard tape
b-2) Wait for 3seconds with F/P "REC" key and "PLAY" key presseed at the same time. < Digitron[ - - ] >
c-3) Repeat the above step(No.b-2), then it finishes the PG adjusting automatically. < Digitron[ PG ] >
d-4) Stop the playback, then it goes out of PG adjusting mode after mony the PG data.
• CONNECTION
TP
(VCR
VIDEO)
(CH2)
VDR BOARD
• WAVEFORM

VCR PART

MEASUREMENT POINT
V.Out
H/SW(TP)
(CH1)
H/SW
(TP)
VCR BOARD
H/SW
Composite
VIDEO
ADJUSTMENT POINT
R/C TRK JIG KEY
OSCILLOSCOPE
R/C KEY
6.5H(416µs)
3-3
SPECIFICATION
6.5 ± 0.5H
CH1 CH2
H/SW "VCR VIDEO" TP
(TP)