Read Sharp XV-C20E (serv.man3) Service Manual online
15
XV-C20E
ELECTRICAL ADJUSTMENT
6
VCO
adjustment
(L4101)
adjustment
(L4101)
1. Keep the unit with no signal input.
2. Make connection between TP4101 and
GND.
3. Connect a frequency counter between
TP4102 and TP4101 (GND).
• Turn the core of L4101 to get the
frequency of 15.625±0.01 kHz.
5
PAL free-
running
frequency (2)
for high speed
(R4312, R4420)
running
frequency (2)
for high speed
(R4312, R4420)
1. Receive the PAL monoscope pattern
signal.
2. Connect the dual-beam oscilloscope to
TP4304 and TP4361.
• Turn R4312 and R4420 to obtain
the same waveform as for the
NTSC free-running frequency (2)
adjustment.
NTSC free-running frequency (2)
adjustment.
No.
Adjustment Item
Adjustment Conditions
Adjustment Procedure
1
Initial setting
Before starting the adjustments, initialize
the adjustment data.
the adjustment data.
Press the factory setting "2" button on
the process remote controller to reset
the adjustment data.
the process remote controller to reset
the adjustment data.
4
3
PLL adjustment
(PAL)
(R4339, R4340)
(PAL)
(R4339, R4340)
1. Receive the PAL monoscope pattern
signal.
2. Connect the dual-beam oscilloscope to
TP4305 and TP4306.
• Turn R4339 and R4340 to obtain the
same waveform as for the NTSC
PLL adjustment.
PLL adjustment.
PLL adjustment
(NTSC)
(R4347, R4349)
(NTSC)
(R4347, R4349)
2
1. Receive the NTSC monoscope pattern
signal.
2. Connect a dual-beam oscilloscope to
TP4305 and TP4306.
• Turn R4347 and R4349 to obtain the
waveform shown below.
NTSC free-
running
frequency (2)
for high speed
(R4341, R4343)
running
frequency (2)
for high speed
(R4341, R4343)
1. Receive the NTSC monoscope pattern
signal.
2. Connect the dual-beam oscilloscope to
TP4304 and TP4361.
• Turn R4341 and R4343 to obtain the
waveform shown below.
1
µ
s
GND
GND
2.5V
2.5V
H-SYNC
TP4305
TP4306
Pulse width to
be the same.
be the same.
1
µ
s
GND
GND
2.5V
2.5V
H-SYNC
TP4304
TP4361
Pulse width to
be the same.
be the same.
NOTE: The settings have been factory-adjusted to their best points. If any of them gets out of spec or after any
relevant part has been replaced, make the related adjustment.
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