Read Sharp VC-MH85 (serv.man9) Service Manual online
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VC-MH705HM/LM
VC-MH815HM/LM,MH85HM
VC-MH715HM,MH835HM
VC-MH815HM/LM,MH85HM
VC-MH715HM,MH835HM
Measuring
instrument
instrument
Mode
Cassette
Dual-trace oscilloscope
Colour TV monitor
Colour TV monitor
Playback
Alignment tape
SERVO CIRCUIT ADJUSTMENT
ADJUSTMENT OF HEAD SWITCHING POINT
Measuring
instrument
instrument
Mode
Cassette
Colour TV monitor
Playback still
Self-recorded tape (SP/LP,EP mode)
(See Note below
(See Note below
1
)
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
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)
1. Remove the front panel and play the alignment tape.
2. Get TP801 short circuited or press press "TEST"key(47H)
2. Get TP801 short circuited or press press "TEST"key(47H)
at Universal remote control to call the test mode.
(LCD will blinking as tracking goes to center)
(LCD will blinking as tracking goes to center)
3. Press "PLAY" key.
Auto PG Mode will be ON and playback mark "
>
"
blinking.
4. Press "STOP" key
"
>
" blinking stops and auto adjustment finished.
5. Check that V-Sync is 6.5
±
0.5H and the waveform is as
shown in Figure 5-2.
Note:
For manual PG Adjustment,press FF or REW key at
the Test Mode to set the tracking in center.
the Test Mode to set the tracking in center.
6.5
±
0.5H
V: 2V/div
CH-1
Head Switching Pulse
Head Switching Pulse
CH-2
Video signal
Video signal
Figure 5-2.
Head
Tape
2
CBZF
2LP
BBZG
4
CBZF
4HiFi
CBZF
1. Play a self-recorded tape.
2. Press the PAUSE/STILL button to freeze the picture.
3. Adjust (+) or (
2. Press the PAUSE/STILL button to freeze the picture.
3. Adjust (+) or (
-
) TRACKING buttons on the remote
control so that the vertical jitter of the picture is mini-
mized.
mized.
Note:
1
Self-recorded tape is a cassette which program was
recorded by the unit being adjusted.
recorded by the unit being adjusted.
2
The FV goes back to the it's initial state when the unit
is put into the system controller reset mode due to
power failure,etc.
In this case, preset the FV once again.
is put into the system controller reset mode due to
power failure,etc.
In this case, preset the FV once again.
Y/C CIRCUIT ADJUSTMENT
CHECKING OF VIDEO E-E LEVEL
Measuring
instrument
instrument
Mode
Input signal
Oscilloscope
E-E or Record
EIA colour bar (1.0Vp-p)
Test point
VIDEO OUT jack
Specification
1.0
±
0.2 Vp-p
1. Connect a 75 ohm terminating resistor to the VIDEO
OUT jack and connect an oscilloscope across this
termi-nating resistor.
(See Note below.)
termi-nating resistor.
(See Note below.)
2. Feed a colour bar signal to the VIDEO IN jack.
3. Make sure that the E-E signal amplitude is 1.0Vp-p as
3. Make sure that the E-E signal amplitude is 1.0Vp-p as
shown in Figure 5-3.
Note:
If the 75 ohm terminating resistor is missing, the signal
amplitude will be doubled.
If the 75 ohm terminating resistor is missing, the signal
amplitude will be doubled.
1.0 Vp-p
Figure 5-3.
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