Electrical Adjustments; Handset; Base Unit - Sony SPP-A973 Service Manual

ELECTRICAL ADJUSTMENTS

3-1. HANDSET

1. Test Mode
Entry— Press "PGM" key and enter " TEST" on keypad.
Alternative entry— Write 99h into LSB of location 9 in EEPROM.
Exit— Press on "OFF" key.
LCD test— Press the "7" key.
Toggle TX power— Press the "0" key.
Increment RF channel— Press the "#" key.
2. Test Equipment Required and Connection
– HAND MAIN BOARD –
C1029
J1003
BATTERY
U1001
3.6V
J1004
3. Verify Procedure
Item Remark
18.4MHz Frequency Error Connect the frequency counter to the test point J1, press "0" key to turn on the TX power. Then, check
the frequency ± 1 kHz. If the result is within ± 1 kHz, then no adjustment required. Otherwise, refer to
item 4. for Adjustment Procedure.
4. Adjustment Procedure
Item Adjustment Element
18.4MHz Frequency Error C1030
SECTION 3
C1030
C1031 – RF UNIT (HS) –
frequency
counter
Remark
1. Remove C1031 from the HAND MAIN board.
2. Solder an 20PF chip capacitor C1030 (1-164-160-11) on the
HAND MAIN board (in parallel of C1029).
3. Connect the frequency counter to the test point J1. Adjust for 0 Hz ± 1 kHz.
– 19 –

3-2. BASE UNIT

1. Test Mode
Entry— Simultaneously press the "HANDSET LOCATOR" key and toggle the "DIAL MODE" switch. When in test mode, the "IN USE"
and "CHARGE" LEDs will be light on.
Alternative entry— Write 99h into LSB of location 9 in EEPROM.
Exit— Remove the AC power adaptor.
Toggle TX power— DIAL MODE switch (S4001)
T (TONE) position : TX ON
P (PULSE) position : TX OFF
Increment RF channel— Press the "INTERCOM" key.
2. Test Equipment Required and Connection
frequency
counter
J1
– RF UNIT (BU) –
J1
3. Verify Procedure
Item
18.4MHz Frequency Error
4. Adjustment Procedure
Item
18.4MHz Frequency Error
– BASE MAIN BOARD – BASE MAIN BOARD
(SIDE B) – (SIDE A) –
Remark
Connect the frequency counter to the test point J1, press "0" key to turn on the TX power. Then, check
the frequency ± 1 kHz. If the result is within ± 1 kHz, then no adjustment required. Otherwise, refer to
item 4. for Adjustment Procedure.
Adjustment Element Remark
C4016 1. Remove C4017 from the BASE MAIN board.
2. Solder an 20PF chip capacitor C4016 (1-164-160-11) on the
BASE MAIN board (in parallel of C4014).
3. Connect the frequency counter to the test point J1. Adjust for 0 Hz ± 1 kHz.
– 20 –
C4014
C4016
U4001
C4017