Read Sharp VC-M315HM (serv.man5) Service Manual online
27
VC-M305HM/LM
VC-M315HM/LM
VC-M315HM/LM
5. ELECTRICAL ADJUSTMENT
Notes:
• Before the adjustment:
• Before the adjustment:
Electrical adjustments discussed here are often required after replacement of electronic components and mechani-
cal parts such as video heads.
Check that the mechanism and all electric components are in good working condition prior to the adjustments,
otherwise adjustments can not be completed.
cal parts such as video heads.
Check that the mechanism and all electric components are in good working condition prior to the adjustments,
otherwise adjustments can not be completed.
• Instruments required:
Blank video cassette tape
DC voltmeter
Screwdriver for adjustment
DC voltmeter
Screwdriver for adjustment
Colour TV monitor
Dual-trace oscilloscope
Dual-trace oscilloscope
Alignment tape (VROCBZF)
Servicing precations
When the IC710 (E
When the IC710 (E
2
PROM) has been replaced, make the following reprogramming. Depending on models, the
IC710(E
2
PROM) has been factry-adjusted for it’s memory function.
It’s therefore necessary to reprogram the memory function for the model in question.
Note that the servo circuit requires readjustments for the head switching point, slow and still modes.
Note that the servo circuit requires readjustments for the head switching point, slow and still modes.
• Location of controls and test points
TP201
Figure 5-1.
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VC-M305HM/LM
VC-M315HM/LM
VC-M315HM/LM
Measuring
instrument
instrument
Mode
Cassette
Oscilloscope
Playback
Aligment Tape (VROCBZF)
Test point
Pin(2) of TP201 (H.SW.P.) to CH-
1, VIDEO OUT jack to CH-2
(CH-1 trigger slope switch at (+),
Internal trigger at CH-1 side.)
1, VIDEO OUT jack to CH-2
(CH-1 trigger slope switch at (+),
Internal trigger at CH-1 side.)
Specification
6.5
±
0.5H (lines)
SERVO CIRCUIT ADJUSTMENT
ADJUSTMENT OF HEAD SWITCHING POINT
1. PB the self-REC tape.
2. Set to SLOW PB mode by pressing the SLOW key.
3. Transmit the TEST(R/C code 47H).Or short the TP801
2. Set to SLOW PB mode by pressing the SLOW key.
3. Transmit the TEST(R/C code 47H).Or short the TP801
on the main PWB once.
4. Adjust the noise bar at the botton of monitor screen
using TRACKING UP,DOWN key until it dissapear.
5. Press the PB key to PB and during this time, press the
PB/STILL for few times repeatedly and during STILL
make sure no noise appear.
Same with the SP, do the 1~5 items.(for LP )
make sure no noise appear.
Same with the SP, do the 1~5 items.(for LP )
~
. For LP, skew will appear at the above.
ADJUSTMENT OF PAL SYSTEM SP/LP SLOW
TRACKING PRESET
TRACKING PRESET
Measuring
instrument
instrument
Mode
Cassette
Monitor Screen
Playback
Self-recorded tape
(SP/LP mode)
(SP/LP mode)
Control
Tracking control buttons (
]
) or (
[
)
Specification
Minimized noise on
monitor screen
monitor screen
1. Insert the Aligment Tape (VRO-CBZF) and set to PB Mode.
2. Transmit the TEST code (R/C code 47H) to VCR.
2. Transmit the TEST code (R/C code 47H) to VCR.
Or, once, short the TP801 at the main PWB
(By doing this,LCD will all light up and become the PB
Tracking Center value.
(By doing this,LCD will all light up and become the PB
Tracking Center value.
~
As for the recover equipment,prepare the memory-remote
control.
But,while adjust the running, at non cassete control unit
condition but have the cassete control JP(TP801 short on
the main PWB), if press TRACKING UP and DOWN key at
the same time, it'll become the TRACKING CENTER (for
Running Ajustment)
control.
But,while adjust the running, at non cassete control unit
condition but have the cassete control JP(TP801 short on
the main PWB), if press TRACKING UP and DOWN key at
the same time, it'll become the TRACKING CENTER (for
Running Ajustment)
3. Again, transmit the PLAY (PB), or Press PLAY Key.After
AUTO PG ADJ mode is finished, make sure the PB Switch-
ing Point is inside standard range.
ing Point is inside standard range.
~
During Flashing of PLAY(casette mark) is AUTO PG ADJ,
finish the AUTO PG ADJ,by light off.
finish the AUTO PG ADJ,by light off.
~
When using the manual PG ADJ,finish the No.2, and it is
able to adjust the PG using FF key or REW key.
able to adjust the PG using FF key or REW key.
Measuring
instrument
instrument
Mode
Cassette
Monitor Screen
Playback still
Self-recorded tape
(SP/LP mode)
(SP/LP mode)
Control
Tracking control buttons (
]
) or (
[
)
Specification
No vertical jitter of picture
ADJUSTMENT OF PAL SYSTEM FV (False
Vertical Sync) OF STILL PICTURE
Vertical Sync) OF STILL PICTURE
1. PB the self-REC tape.
2. Press the PAUSE/STILL key and STILL the picture.
3. As looking at the monitor, using the TRACKING UP+,
2. Press the PAUSE/STILL key and STILL the picture.
3. As looking at the monitor, using the TRACKING UP+,
DOWN
−
adjust till the perpendicular jitter dissapear.
~
For the LP also, while PB the self-REC tape, for STILL,
it is better to confirm that no perpendicular jitter appear.
it is better to confirm that no perpendicular jitter appear.
CH-2
Video output
CH-1
V: 2V/div
V: 1V/div
TRIG INT CH-1,H:50
µ
sec/div
6.5H
29
VC-M305HM/LM
VC-M315HM/LM
VC-M315HM/LM
Observe the video output using the oscilloscope and confirm as
the above diagram
the above diagram
*
V:200mV/div
H:20
H:20
µ
sec/div
Measuring
instrument
instrument
Mode
Cassette
Spectrum
Analyzer
Analyzer
Recorded
Self-recorded tape
Test point
YC CHIP Pin98
Specification
3.8MHz
±
50KHz
ADJUSTMENT OF FM Carrier Confirmation
VIDEO
PAL Colour Bar(1Vp-p)
Measuring
instrument
instrument
Mode
Cassette
Oscilloscope
Recorded
Self-recorded tape
(SP/LP mode)(See Note below)
(SP/LP mode)(See Note below)
Test point
VIDEO OUT 21PIN or RCA Port
(75
(75
Ω
Terminal)
Specification
1.0
±
0.2Vp-p
Y/C CIRCUIT ADJUSTMENT
ADJUSTMENT OF EE Level Confirmation
VIDEO
PAL Colour Bar(1Vp-p)
Measuring
instrument
instrument
Mode
Cassette
Spectrum
Analyzer
Analyzer
Recorded
Self-recorded tape
Test point
YC CHIP Pin98
Specification
4.8MHz
±
100KHz
ADJUSTMENT OF Deviation Confirmation
VIDEO
Colour Bar(1Vp-p)
3.80
4.80MHz
A
f
<Deviation>
Confirm the white peak frequency follow
the standard value.
(the deviation between shinkchip and f
white peak is 1MHz
Confirm the white peak frequency follow
the standard value.
(the deviation between shinkchip and f
white peak is 1MHz
±
100KHz)
Measuring
instrument
instrument
Mode
Cassette
Oscilloscope
Self-recorded/Playback tape
Test point
YC CHIP Pin98
Specification
about300mVp-p
ADJUSTMENT OF REC Current Confirma-
tion
tion
VIDEO
Colour Bar(1Vp-p)
<Diagram A>
Confirm the Sink chip is as the
left diagram <Diagram A>.
left diagram <Diagram A>.
1.0Vp-p
Sink Chip
Recorded
30
VC-M305HM/LM
VC-M315HM/LM
VC-M315HM/LM
Mode
EE
ADJUSTMENT OF Receive Image CH
Confirm that there is no noise and beat in the receiving strenght
and weakness electrics signal.
and weakness electrics signal.
Measuring
instrument
instrument
Mode
Cassette
Oscilloscope
Playback
Self-recorded/Playback tape
Test point
VIDEO OUT port
(75
(75
Ω
terminal)
Specification
Check place 1.
(1
(1
±
0.2Vp-p)
VIDEO
Colour Bar
ADJUSTMENT OF PB Level Confirmation
1.0Vp-p
Measure the picture out-
put port using the 75
put port using the 75
Ω
ter-
minal Oscilloscope and
confirm the diagram same
as the left diagram.
confirm the diagram same
as the left diagram.
~
V:200mV/div
H:20
H:20
µ
sec/div
Measuring
instrument
instrument
Mode
Cassette
Oscilloscope
Recorded/Playback
Self-recorded/Playback tape
Test point
VIDEO OUT
VIDEO
mono-sco
ADJUSTMENT OF S-PICTURE Confirmation
Receive the mono-sco.
Confirmation : make sure no black split at the mono-sco
picture during the self-Rec PB when the S-PICTURE is
ON with the S-PICTURE ON/OFF,make sure the picture
level at the wedge part is change.
Confirmation : make sure no black split at the mono-sco
picture during the self-Rec PB when the S-PICTURE is
ON with the S-PICTURE ON/OFF,make sure the picture
level at the wedge part is change.
(S-PICTURE ON - about 260 line)
(S-PICTURE OFF about 240 line)
(S-PICTURE OFF about 240 line)
Measuring
instrument
instrument
Mode
Digital Voltmeter
EE
Specification
2.5
±
0.5V
TUNER/IF Circuit ADJUSTMENT
ADJUSTMENT OF AFT Adjustment
Confirmation(except France)
Confirmation(except France)
Test point
TU101 pin23
E-12ch, Input level 70dB
µ
While selecting channel input TEST MODE(press once
on TEST KEY R/C) and select E-12ch.
on TEST KEY R/C) and select E-12ch.
(Just Tuning)
Adjustment
ADJUSTMENT OF AFT Adjustment
Confirmation(France)
Confirmation(France)
F-10ch, Input level 70dB
µ
While selecting channel input TEST MODE(press once
on TEST KEY R/C) and select F-10ch.
(Just Tuning)
on TEST KEY R/C) and select F-10ch.
(Just Tuning)
F-4ch, Input level 70dB
µ
While selecting channel input TEST MODE(press once
on TEST KEY R/C) and select F-4ch.
(Just Tuning)
on TEST KEY R/C) and select F-4ch.
(Just Tuning)
HM
I40ch
LM
I-Jch
Measuring
instrument
instrument
Mode
Digital Voltmeter
EE
Specification
2.5
±
0.5V
Test point
TU101 pin23
