Preparation For Adjustment; Power Supply Voltage Adjustment - Sony BKPF-L752 Maintenance Manual

2-2. Preparation for Adjustment

2-3. Power Supply Voltage Adjustment

2-2. Preparation for Adjustment
1. Extend the DAC-38 board with a extension board.
2. Write down the customer settings of the switch (S3) on
the DAC-38 board in following table.
3. Set the switch S3 as follows:
Ref. No. (Address) Setting at adj.
S3 (F-1) No. 1: OFF
No. 2: OFF
No. 3: OFF
No. 4: OFF
4. Install the main board (ADC-40 board) of the audio
A/D converter board (BKPF-L751's audio input/
output gain in a factory default condition) to the
interface unit.
Factory default condition (RV405, 406, 407, 408/
ADC-40 board):
Each VR was completed the adjustment so as to
convert a +4.0 dBm to _20 dB FS.
5. Install the connector panel of the audio A/D converter
board (BKPF-L751) to the interface unit after setting
the LOOP/WORD switch to WORD CLK OUT (upper
position).
6. Turn on the power of equipment, and warm up them
for about ten minutes.
D3
D814
D815
RV101
RV201
RV301
RV401
E3
ON
E6
1 2 3 4
1
RV3
DAC-38 Board (Side A)
2-2 (E)
Customer setting
OFF
OFF
E4
E7
TP4
TP3
E2
S3
E1
TP2 TP1
1 1
RV2 RV1
E8
2-3. Power Supply Voltage Adjustment
Measuring equipment: Digital voltmeter
1. Set the digital voltmeter as follows:
Range: AUTO
Mode: DC V
+ + + + + 5 V adjustment for Analog line
2. Connect the probe of the digital voltmeter as follows:
+: TP1/DAC-38 (G-2)
_: E7/DAC-38 (C-2)
3. Adjust the voltage on the digital voltmeter.
Adjustment point: 1RV1/DAC-38 (G-2)
Specification: 4.75 0.05 V dc
+ + + + + 5 V adjustment for Digital line
4. Connect the probe of the digital voltmeter as follows:
+: TP2/DAC-38 (F-2)
_: E2/DAC-38 (F-2)
5. Adjust the voltage.
Adjustment point: 1RV2/DAC-38 (F-2)
Specification: 4.75 0.05 V dc
12 V adjustment
6. Connect the probe of the digital voltmeter as follows:
+: TP3/DAC-38 (D-3)
_: TP4/DAC-38 (D-3)
7. Adjust the voltage.
Adjustment point: 1RV3/DAC-38 (E-2)
+25.10 0.05 V dc
Specification:
8. Connect the probe of the digital voltmeter as follows:
+: TP3/DAC-38 (D-3)
_: E7/DAC-38 (C-2)
9. Check the voltage.
+12.55 0.15 V dc
Specification:
10. Connect the probe of the digital voltmeter as follows:
+: E7/DAC-38 (C-2)
_: TP4/DAC-38 (D-3)
11. Check the voltage.
_12.55 0.15 V dc
Specification:
n
After adjusting the power supply voltage, be sure to
perform "2-4. Input/Output Gain Adjustment".
BKPF-L752