Panasonic SA-PM23P / SA-PM23PC Service Manual ▷ View online
12 Procedure for Checking Operation of Individual Parts of
Deck Mechanism Unit
12.1. Operation Check with Cassette Tape
1. Pull up the EJECT lever using a rubber band. (Fig. 6)
2. Supply DC5V to MOTOR. (
2. Supply DC5V to MOTOR. (
→ MOTOR rotates.) (Fig. 5)
3. Insert a cassette tape to the unit.
4. Supply DC9V to the plunger, and turn the power ON and OFF. (
4. Supply DC9V to the plunger, and turn the power ON and OFF. (
→ Power +PL, -PL) (Fig. 5)
a. FWD PLAY: Supply the plunger power in a flash. (ON: approx. 5msec)
b. FWD FF: Supply the plunger power in a flash at PLAY mode. (ON: approx. 5msec)
c. STOP: Supply the plunger power in a flash at FWD FF mode. (ON: approx. 5msec)
d. REV PLAY: Supply the plunger power in a normal timing at STOP mode. (ON: approx. 200msec)
e. REV REW: Supply the plunger power in a flash at REV PLAY mode. (ON: approx. 50msec)
f.
b. FWD FF: Supply the plunger power in a flash at PLAY mode. (ON: approx. 5msec)
c. STOP: Supply the plunger power in a flash at FWD FF mode. (ON: approx. 5msec)
d. REV PLAY: Supply the plunger power in a normal timing at STOP mode. (ON: approx. 200msec)
e. REV REW: Supply the plunger power in a flash at REV PLAY mode. (ON: approx. 50msec)
f.
STOP: Supply the plunger power in a flash at FF mode. (ON: approx. 50msec)
Repeat the operation (
Repeat the operation (
→ FWD PLAY)
(Note) Other operation may start if a timing of supplying the plunger power is missed.
12.1.1. Connection Status between Mechanism and Power Supply (Motor, Plunger)
12.1.2. Operative Parts of Deck Mechanism Unit (EJECT lever fitted with rubber band,
Plunger/Rib operation)
Fig. 6
12.2. Operation Check without Cassette Tape
1. Pull up the EJECT lever using a rubber band. (Fig. 6)
2. Supply DC5V to MOTOR. (
2. Supply DC5V to MOTOR. (
→ MOTOR rotates.)
3. Lift up the mechanism unit’s plunger/rib with the tip of a negative screwdriver, and operate the unit in the same timing as
supplying the power. (Fig. 7)
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SA-PM23P / SA-PM23PC
Fig. 7
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SA-PM23P / SA-PM23PC
13 Measurement And Adjustments
13.1. Cassette Deck Section
13.1.1. Requirements
· Test tape (QZZCFM) (QZZCWAT)
· Normal blank cassette tape (QZZCRA)
· Digital frequency counter
· Oscilloscope
· Electrical voltmeter
· Headphone jack output jig (Fig. 8)
· Normal blank cassette tape (QZZCRA)
· Digital frequency counter
· Oscilloscope
· Electrical voltmeter
· Headphone jack output jig (Fig. 8)
13.1.2. Setting of Unit
· VOLUME: MAX
13.1.3. Preparations
1. Apply under [9. Assembling and Disassembling].
2. Remove 4 screws from the mechanism unit to disassemble. under [9. Assembling and Disassembling].
3. Connect the headphone jack output jig (Fig. 8) to headphone jack.
2. Remove 4 screws from the mechanism unit to disassemble. under [9. Assembling and Disassembling].
3. Connect the headphone jack output jig (Fig. 8) to headphone jack.
Fig. 8
Fig. 9
13.1.4. Tape Speed Adjustment
· Normal speed adjustment (only during forward playback)
(Product reference value: 3,000±90Hz)
1. Connect a frequency indicator. (Fig. 12)
2. Playback the middle portion of the test tape (QZZCWAT).
3. Adjust the motor screw so that the following output level is produced. (Fig. 10)
2. Playback the middle portion of the test tape (QZZCWAT).
3. Adjust the motor screw so that the following output level is produced. (Fig. 10)
Adjustment Range: 3,000 ± 90Hz (a constant speed)
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SA-PM23P / SA-PM23PC
Fig. 10
Fig. 11
13.1.5. Bias Voltage Check
1. Connect an electrical voltmeter. (Fig. 9) (Fig. 12)
2. Set the function to “TAPE” position.
3. Insert a normal blank cassette tape (QZZCRA).
4. While pressing and holding down [REC (
2. Set the function to “TAPE” position.
3. Insert a normal blank cassette tape (QZZCRA).
4. While pressing and holding down [REC (
/
)] button, press [TAPE (
)] button to pause the recording mode. (Repeat
pressing the buttons till the recording pause mode is activated.)
5. Check that the output level is within the standard range.
Standard Range: 16 ± 3mV
Fig. 12
13.1.6. Bias Frequency Check
1. Connect a digital frequency counter (Fig. 13).
2. Set the function to “TAPE” position.
3. Insert a normal blank cassette tape (QZZCRA) and press “REC” mode on main unit.
4. Check that the output frequency is within the standard range.
2. Set the function to “TAPE” position.
3. Insert a normal blank cassette tape (QZZCRA) and press “REC” mode on main unit.
4. Check that the output frequency is within the standard range.
Standard Value: 98 ±8 kHz
Fig. 13
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SA-PM23P / SA-PM23PC
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