Electrical Adjustments; Base Unit - Sony SPP-A2770 Service Manual

0 dBm = 0.775 V

BASE UNIT

• Make the set in the test mode. (See page 12)
Note:
The test mode in this set includes the test items that use normal set
only, and the test items that need the panel (BASE CABINET (UP-
PER) ASSY) to be replaced with that for the SPP-A2780. (Refer to
page 4)
Items that use normal set only (Test case 1)
• TSET A
• TSET C
• TSET F
• Erase
Items that use the panel for SPP-A2780 (Test case 2)
• TSET D
• TSET E
1. Power Failure Test
Procedure: (Use the panel for normal set)
1. Connect between TP338 and TP306 (GND) on the BASE
MAIN board by lead wire.
2. In the test mode idling status, press the
display "–A".
[ANSWER ON/OFF]
3. Check that the
up when connect between TP203 and TP306 (GND) on the
BASE MAIN board.
2. Ring Detection Test
Procedure: (Use the panel for normal set)
1. In the "–A" status, connect the base unit to telephone line.
[IN USE]
2. Check that the LED on the base unit lights up when
call the base unit.
3. Charge Current and CHARGE LED Test
Setting:
digital voltmeter
+
47 Ω/1W
–
Procedure: (Use the panel for normal set)
1. Connect equipments as the figure above.
2. In the "–A" status, check that the value of digital voltmeter is
[CHARGE]
5.6 to 5.8 V and the
up.
SECTION 5

ELECTRICAL ADJUSTMENTS

[MEMO REC]
key to
LED on the base unit lights
Base unit
charge terminal
+
charge terminal
–
LED on the base unit lights
4. C-ID Input Level Measurement
Setting:
feeding bridge
Line
Line
Trunk
Output
Input
GND
audio analyzer
1.2 kHz, –27 dBm
LPF: 30 kHz ON
Procedure: (Use the panel for normal set)
1. Connect equipments as the figure above.
2. In the test mode idling status, press the
key to display "–F".
3. Set the output level of audio analyzer to –17 dBm (1.2 kHz,
LPF=30 kHz ON).
4. Check that the value of audio analyzer is –15 to –21 dBm.
5. Between Microphone and Line Signal Level
Measurement
Setting:
feeding bridge
Line
Line
Trunk
600 Ω
10 µF
Input
Output
GND
audio analyzer
1.2 kHz, –36 dBm
LPF: 30 kHz ON
Procedure: (Use the panel for normal set)
1. Connect equipments as the figure above.
2. In the test mode idling status, press the
key to display "–F", and press the
set the speaker path test 2 mode.
3. Set the output level of audio analyzer to –27 dBm (1.2 kHz,
LPF=30 kHz ON).
4. Check that the value of audio analyzer is –2 to –8 dBm.
SPP-A2770
Base unit
TP101
TP102
TP413
TP306 (GND)
[GREETING PLAY]
Base unit
TP101
TP102
TP475
+
TP306 (GND)
[GREETING PLAY]
[GREETING REC]
key to
19