Sharp VL-A111UL Service Manual - Page 26

Battery shutoff voltage adjustment, 4. TEST mode, 6. VCR adjustments

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VL-A111U/AH131U VL-AH151U/AH161U 6-4. TEST mode TEST No. Title 1 Sensor Off 2 Mecha Adjustment mode 3 Shut Off Adjustment 4 Error Display 5 PASS mode 6 Cam Adjustment mode 7 VCR Adjustment mode 8 Head Switching Point ADJ. Contents All the sensors are off except for the cassette control switch, DEW sensor, and battery sensor. ATF sampling is restricted to the central part. Shutoff voltage value is written in E2PROM. - Track shift (1/4 shift) - - If "TEST 8" is selected for normal tape playback, Head Switching Pint is automatically adjusted. Note: If "T-03" is selected in the CAM mode while a recordable tape is loaded, the unit starts recording automatically. T-01 1 Select No with "FF" or "REW" key. 2 Confirm with "PB" key. 6-5. Battery shutoff voltage adjustment 1) Supply power to the main unit, using the variable-voltage DC power supply (range of 2.5V to 5.0V). 2) Set the CAM/OFF/VCR SW to CAM to switch to the camera mode. 3) Load a recordable tape and set the main unit to CAM REC. PAUSE. 4) Set the main unit to TEST mode No. 3, and start recording. 5) Measure voltage between TL2911(+) and TL2914(GND), and adjust the supply voltage to 3.1V. 6) The adjustment is complete if "BATTERY" is displayed on the monitor screen for a second when the PLAY key of operation unit is pressed. 7) The adjustment is regarded as proper if the auto shut-off is actuated after the warning is displayed when the TEST mode is cancelled. * In case of automatic adjustment of shut-off voltage, adjustment is impossible if voltage is above 3.1V ± 0.2V. If the adjustment is made at 2.9V or below, the low-voltage operation may become unstable. 6-6. VCR section adjustments 6-6-1. VCR section adjustments jigs • Measuring instruments: *Color monitor TV set *Digital voltmeter *DC power supply *Audio generator (CR oscillator) *Alignment tape (JiGWR5-5NSP) (JiGWR5-8NSE) *Oscilloscope *Frequency counter *Signal generator *AV output cable (accessory) *Video recording tape (For Y/C, audio and servo adjustments) *DC cable (AC adapter accessory) *Video extension cables *Vector scope *AC adapter 26

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26
VL-A111U/AH131U
VL-AH151U/AH161U
6-5. Battery shutoff voltage adjustment
1)
Supply power to the main unit, using the variable-voltage DC power supply (range of 2.5V to 5.0V).
2)
Set the CAM/OFF/VCR SW to CAM to switch to the camera mode.
3)
Load a recordable tape and set the main unit to CAM REC. PAUSE.
4)
Set the main unit to TEST mode No. 3, and start recording.
5)
Measure voltage between TL2911(+) and TL2914(GND), and adjust the supply voltage to 3.1V.
6)
The adjustment is complete if "BATTERY" is displayed on the monitor screen for a second when the PLAY key of operation unit
is pressed.
7)
The adjustment is regarded as proper if the auto shut-off is actuated after the warning is displayed when the TEST mode is cancelled.
*
In case of automatic adjustment of shut-off voltage, adjustment is impossible if voltage is above 3.1V
±
0.2V.
If the adjustment is made at 2.9V or below, the low-voltage operation may become unstable.
6-4. TEST mode
TEST No.
Title
Contents
1
Sensor Off
All the sensors are off except for the cassette control switch, DEW sensor, and battery
sensor.
2
Mecha Adjustment mode
ATF sampling is restricted to the central part.
3
Shut Off Adjustment
Shutoff voltage value is written in E
2
PROM.
4
Error Display
—
5
PASS mode
Track shift (1/4 shift)
6
Cam Adjustment mode
—
7
VCR Adjustment mode
—
8
Head Switching Point ADJ.
If “TEST 8” is selected for normal tape playback, Head Switching Pint is automatically
adjusted.
Note: If “T-03” is selected in the CAM mode while a recordable tape is loaded, the unit starts recording automatically.
T-01
1
Select No with “FF” or “REW” key.
2
Confirm with “PB” key.
•
Measuring instruments:
*Color monitor TV set
*Oscilloscope
*DC cable (AC adapter accessory)
*Digital voltmeter
*Frequency counter
*Video extension cables
*DC power supply
*Signal generator
*Vector scope
*Audio generator (CR oscillator)
*AV output cable (accessory)
*AC adapter
*Alignment tape (JiGWR5-5NSP)
*Video recording tape
(JiGWR5-8NSE)
(For Y/C, audio and servo adjustments)
6-6. VCR section adjustments
6-6-1. VCR section adjustments jigs