LG V9120W Service Manual page 94

DECK MECHANISM ADJUSTMENT
5-2. Tape Path Check between Pinch Roller and
Take up Guide (Check in the Rev Mode)
1) Check the tape pass status between the pinch roller and
the take-up guide.(Check there is crumpling of the tape
pass and folding of the take-up guide.)
1) (1) When holding of the take-up guide bottom occurs
Turn the tilt adjusting screw (C) clockwise and travel it
stably to ensure there is no crumbling or folding of the
tape.
1) (2) When holding of the take-up guide top occurs
Turn the tilt adjusting screw (C) anti-clockwise and
5-3. Fine Adjustment (Azimuth Adjustment)
Fixtures and tools used
• Oscilloscope
• Standard test tape
(only for SP)
• Driver (+) Type Ø 4
Adjustment Procedure
1) Connect the probe of Oscilloscope to the audio output
jack.
2) Ensure that Audio 1KHz, 7KHz output is flattened at the
maximization point by adjusting the Azimuth adjusting
screw (A).
6. X-distance Adjustment
Purpose of adjustment : To maintain compatibility with other VCR (VCP).
Fixtures and tools used
• Oscilloscope
• Standard test tape
(only for SP)
• Driver (+) Type Ø 4
Adjustment Procedure
1) After releasing the auto tracking, lightly turn the fixing
screw. Turn the (+) type driver (Ø 3 ~ Ø 4) on the X-dis-
tance adjusting hole to the right or left. Adjust the RF
envelope level to the maximum point and then fix the fix-
ing screws.
2) For the 31mm head, adjust it with the SP tape recorded
in the width of 31mm since the head travels on the tape
track only for SP with the width of 58mm.
4-17
Connection position
• Audio Output Jack
Connection position
• CH-1: PB RF Envelope
• CH-2: NTSC ; SW 30Hz
PAL:SW 25Hz
• Head switching output
point
• RF Envelope output
point
travel it stably to ensure there is no crumbling or fold-
ing of the tape.
1) 2) Check there is folding of the tape at the bottom or top
of the take-up guide in cutting-off the REV mode
CAUTIONS
If the RF waveform is changed after adjusting the A/C head,
perform fine adjustment to ensure the RF waveform is flat-
tened.
VCR (VCP) status
• Play the standard test
• Tape, 1KHz, 7KHz.
1KHz
A: Maximum
Fig. C-5-4
VCR (VCP) status
• Play the standard test
tape.
Connection Diagram
X-distance Adjusting Hole
Fixing Screw
Azimuth
Adjustment
Screw(A)
RF ENVELOPE OUTPUT POINT
HEAD RF SWITCHING OUTPUT POINT
Adjustment position
• Azimuth Adjusting
Screw (A)
• Height Adjusting Screw
(B)
B: Minimum
Adjustment position
Left
Grove of Base A/C
Right
Tilt Adjusting Screw (C)
Height Adjusting
Screw (B)
Fig. C-6
OSCILLOSCOPE
CH-1 CH-2
7KHz