Switching Regulator (Aps-132 M Board) Adjustments; Preparation; System Minimum Frequency Adjustment; Vs System Minimum Frequency Adjustment - Sony PFM-42B1 Service Manual

3-7. Switching Regulator
(APS-132 M Board) Adjustments

3-7-1. Preparation

1. Remove the switching regulator from the set, and
adjust it under no load.
2. If adjusting the switching regulator with each output
loaded, set as follows.
. . . . . Load on each output
Output Pin No.
CN4 1 pin
VCC
CN5 2 pin
VS
CN5 5 pin
VA
CN6 3 pin
AUDIO +B
CN7 2 pin
STBY +5 V
CN7 5 pin
5VD
CN7 8 pin
6.2 V
CN7 != pin
13.5 V
CN7 !] pin
13 V
3-7-2. 13 V System Minimum Frequency

Adjustment

1. Apply 18 V DC to both ends of C169.
2. Connect a frequency counter between gate and source
of Q153.
Note : As the input of frequency counter, use 10 : 1 oscilloscope probes and
raise the input impedance.
3. Adjust the RV150 so that the oscillation frequency is
93 0.5 kHz.
3-7-3. VS System Minimum Frequency
Adjustment
1. Short between pin-3 and pin-4 of PH501.
2. Apply 18 V DC to both ends of C169.
3. Connect a frequency counter between gate and source
of Q503.
Note : As the input of frequency counter, use 10 : 1 oscilloscope probes and
raise the input impedance.
4. Adjust the RV500 so that the oscillation frequency is
49 0.5 kHz.
PFM-42B1, PFM-42B1E
3-7-4. VA System Minimum Frequency
1. Short between pin-3 and pin-4 of PH701.
2. Apply 18 V DC to both ends of C169.
3. Connect a frequency counter between gate and source
Note : As the input of frequency counter, use 10 : 1 oscilloscope probes and
4. Adjust the RV700 so that the oscillation frequency is
MIN MAX

3-7-5. PFC Voltage Adjustment

1.0 A 5.0 A
0.5 A 1.7 A
1. Set the load on each output to the minimum.
0.5 A 1.5 A
2. Apply 100 V AC.
0.05 A 1.0 A
3. Turn the STBY signal ON. (short between CN7 pin-1
0.2 A 0.3 A
1.2 A 1.8 A
4. Adjust the RV300 so that the voltage across C115 is
0.6 A 1.0 A
0.5 A 1.0 A
0.4 A 1.0 A
3-7-6. 5 V Adjustment
1. Set the load on each output to the minimum.
2. Apply 100 V AC.
3. Adjust the RV201 so that the voltage of STBY +5 V
3-7-7. 13.5 V Adjustment
1. Set the load on each output to the minimum.
2. Apply 100 V AC.
3. Turn the STBY signal ON. (short between CN7 pin-1
4. Adjust the RV250 so that the voltage of 13.5 V output
Adjustment
of Q703.
raise the input impedance.
65 0.5 kHz.
and pin-2).
385 2 V.
output (between CN7 pin-2 and pin-6) is 5.12
and pin-2).
(between CN7 pin-12 and pin-11) satisfies
13.7 0.05 V.
0.03 V.
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