Service manual

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

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