Sharp VC-M314 (serv.man8) Service Manual ▷ View online
33
VC-M314HM
VC-MH834HM
VC-MH834HM
ADJUSTMENT OF LINE3(FRONT) INPUT
Level Confirmation HIFI Lch, Rch
Level Confirmation HIFI Lch, Rch
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
Monitor Screen
EE
Specification
<On Screen Display>
Jumper List
Jumper List
On Screen Display confirm Display
Reference
Reference
TIMER Circuit ADJUSTMENT
ADJUSTMENT OF Timer Initial JP and Y/C
Rec Current Confirmation
Rec Current Confirmation
Measuring
instrument
instrument
Mode
Cassette
Voltmeter
EE
Self-recorded tape
Test point
AUDIO OUT
Specification
-3.8
±
2dBs
VIDEO
Optional
AUDIO
AUDIO IN at 1KHz -3.8dBs
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
P1501 pin 1
TU1401 pin23
TU1401 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
P1501 pin 1
TU1401 pin23
TU1401 pin23
Display eg:
JP :
0
0
3
4
3
0
0
0
1
4
HEX CODE for Initial Jumper
YC :
34
34
07
07
PAL
PAL
NTSC
NTSC
SP
LP/EP
SP
EP
VM : F8FB
←
Video Mode
NOR__
←
ROM Version
1. During EE mode, send the TEST Code (R/C code 47H)
to VCR and hold the Test code, do not let go.
2. While sending the TEST code, the monitor screen will
display the initial JP and Y/C Rec Current setting,
Video mode and ROM Version condition.
Video mode and ROM Version condition.
3. After confirmation, Release the TEST code (R/C code
47H), display will return to EE mode.
34
VC-M314HM
VC-MH834HM
VC-MH834HM
Power Circuit ADJUSTMENT
ADJUSTMENT OF Output Voltage Confirm
ADJUSTMENT OF Over Load Characteristic
Confirmation
Confirmation
Item
Test point
Specification
Fix Load
AT 12V
AT between 12Vline~GND
Output above 11.0V 2.0~2.2A(over load)
AT 25.5V AT between 25.5Vline~GND Output above 25.0V
Measuring
instrument
instrument
Oscilloscope
ADJUSTMENT OF Power Consumption Con-
firmation
firmation
Item
Test point
Specification Fix Load
AT 12V
AT between 12Vline~GND
DC 12.0V
±
0.5V
360mA+actual load
AT 5V
AT between 5Vline~GND
DC 5.2V
±
0.20V
18mA+actual load
AT 39V
AT between 39Vline~GND
DC 38.0V
±
2.0V
actual load
AT 25.5V AT between 25.5Vline~GND DC 25.5V
±
0.5V
actual load
Measuring
instrument
instrument
Digital Voltmeter
<Setting Condition>
1. Power Supply : AC190V(50Hz)
2. Surroung temperature Setting : 20ºC
1. Power Supply : AC190V(50Hz)
2. Surroung temperature Setting : 20ºC
±
10ºC
3. Load connect place : between AT 5V
→
AC connector
8
PIN~AC connector
1
PIN
(High
speed)
: between
AT25.5V
→
AC
5
PIN~AC
2
PIN
(Other
model) : between
AT12V
→
AC
5
PIN~AC
2
PIN
When apply the over load at the AT12V/AT25.5V output
for every 170msec, confirm that the output is 11.0V/25.0V
for every time.
for every 170msec, confirm that the output is 11.0V/25.0V
for every time.
70
100
2.2A
0.65A
(A)
(msec)
Measuring
instrument
instrument
Mode
Fix Load
Power Consumption device
Power off
actual load
Test point
AC Plug
Specification
2.5W MAX
1.Power supply : AC230V(50Hz)
2.Surround Temperature Setting : 20ºC
2.Surround Temperature Setting : 20ºC
±
10ºC
IGR(MPX) Circuit ADJUSTMENT
ADJUSTMENT OF Separation Confirmation
Test point
RCA AUDIO OUT
Specification
R-Lch more than 30dB
1. Receive the IGR Bilingual Broadcasting (STEREO).
(Signal content L-ch
±
0kHZ dev)
(Signal content R-ch
400Hz 0
±
50kHz dev)
2. Connect the RCA AUDIO out put L-ch to Voltmeter.
(weight : flat)
35
VC-M314HM
VC-MH834HM
VC-MH834HM
1
0
1
1
1
10
1
1
1
1
1
0
1
0
0
0
1
0
1
0
0
0
1
0
0
0
0
0
1
0
0
0
1
0
1
0
0
0
1
0
S sensor
Open
Close
Mode detection inside
sensor A
1
1
1
0
0
0
0
0
0
Mode detection outside
sensor B
0
1
1
1
1
0
1
1
0
CS/EJ
ULD
PU1
PU2
VSR
PB
SLOW
FF
STOP
Cam graph E
25
20
15
10
5
0
60
120
180
240
300
380
G mechanical timing
Mode check
Cam mark
Mode detection outside
(D709 SW B)
Mode detection inside
(D708 SW A)
0
19.812
81
179
233
200
265
282
316
334
10.354
12.812
CA/END
CS/EJ
UL
PU1
PU2
VSR
PB
SLOW
FF
STOP
Mode detection outside
Mode detection inside
S sensor
EJ
UL
PU
PU2
VSR
PB
SLW
FF
STP
0
1
1
0
1
1
0
0
0
0
0
1
0
0
1 or 0
Loading motor turns in reverse
direction and master cam
counterclockwise.
CASSETTE INSERTION STOP
Cassette
inserting
Full-
loading
YES
YES
YES
NO
NO
NO
Unloading
Loading motor starts in normal
direction and master cam counter
clockwise.
Does mechanism position sw.
come off within 2.5 sec.?
Are start/end sensors at low level
before cassette insertion ?
Insert cassette.
Double action rack slides.
Drum motor starts.
Tape loading.
Pinch roller comes into contact.
Cam switch is at PB position.
Loading motor stop.
Is drum FG pulse outputted ?
End
End
Cassette is ejected and loading
motor stops.
Start sensor close.
(Cassette is judged
caught halfway.)
(Cassette LED or some other part
is judged defective.)
6. MECHANISM OPERA
TION FLOWCHART
AND TROUBLESHOOTING GUIDE
MECHANISM OPERATION FLOWCHART
36
VC-M314HM
VC-MH834HM
VC-MH834HM
STOP REC/PLAY
PLAY STILL
PLAY VSR
VSR PLAY
Capstan motor turns
counterclockwise.
Is take-up reel sensor signal
outputted ?
End
Press REC/PLAY key.
Picture appears.
Unloading
Set capstan motor to search
speed.
End
Press FF key.
PLAY VSF
REC/PLAY STOP
Capstan motor turns in
reverse direction.
Loading motor turns in
counterclockwise direction
and master cam clockwise.
Slow brake comes into
contact with capstan motor.
Slow brake
pressing
Cam switch is at STILL
position.
End
Capstan motor stops.
Press STOP key.
Loading motor stops.
End
Stop capstan motor.
NO
YES
Press STILL key.
Pinch
roller
releasing
Idler
swinging
Pinch
roller
pressing
Loading motor turns
clockwise and master
cam counterclockwise.
Turn capstan motor in
reverse direction.
Turn loading motor
counterclockwise.
Cam switch is at VSR
position.
Set capstan motor to search
speed.
Is take-up reel sensor signal
outputted ?
Press REW key.
Release pinch roller.
Cam switch is at PU2 position.
Cam switch is at PU1 position.
Stop loading motor.
Press pinch roller.
Loading motor turns clockwise.
Release the supply auxiliary
brake.
Stop loading motor.
End
Unloading
Cam switch is at PB position.
End
Press PLAY Key.
Loading motor turns counter-
clockwise and master cam
clockwise.
Capstan motor turns
counterclockwise. PB speed.
NO
YES
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