Panasonic KX-FC255CX-S, Service Manual

Page: 139 / 256

139
KX-FC255CX-S
12.5.13.2. Troubleshooting for Speakerphone
When the customer’s telephone line corresponds to the following conditions and transmission signal of SP-Phone is interrupted,
performing the next set up to a cordless handset will improve it to some extent.
Conditions
1. When customer’s line has less line loss.
ex.) The customer is using optical fiber, ISDN terminal adaptor, or PBX.
In this case, receiving signal is strong and it may affect transmission signal.
2. When the other party is talking from noisy place.
ex.) The other party is using cellular phone. The background noise is very loud.
In this case, the noise from the other party (i.e. surrounding noise) may affect transmission signal.
Setting Method
• Change the address of EEPROM (0144) from 0
×
00 to 0
×
01.
12.5.14. Troubleshooting by Symptom (Charger Unit)
12.5.14.1. Check Point (Charge Unit)
Note:
After the measuring, suck up the solder of TP.
The connection of adjustment equipment is as shown in
Adjustment Standard (Charger Unit) (P.177).
( P ) Timing Confirmation - Follow steps 1 to 3 of (K) .
4.Confirm that the Timing accuracy is < ± 2.0ppm.
IC1, IC4, C66,
C58, C57,
C50, C53,
C52, R52,
C60, C61
( Q )* RSSI Level Confirmation - Follow steps 1 to 3 of (K) .
4.Set DECT tester power to -81dBm.
5.Execute the command “readrssi”.
6.Confirm that the returned value is 1B ± 8 (hex).
7.Set DECT tester power to -63dBm.
8.Execute the command “readrssi”.
9.Confirm that the returned value is 23 ± 8 (hex).
IC1, IC4, C66,
C58, C57,
C50, C53,
C52, R52,
C60, C61
( R ) Power RAMP Confirma-
tion
- Follow steps 1 to 3 of (K) .
4.Confirm that Power RAMP is matching.
IC1, IC4, C66,
C58, C57,
C50, C53,
C52, R52,
C60, C61
( S ) Audio Check and Confir-
mation
- 1. Link to BASE which is connected to Line Simulator.
2. Set line voltage to 48V and line current to 40mA.
3. Input -45dBm/1KHz to MIC and measure Line output level.
4. Confirm that the level is -8.5dBm ± 2dBm and that the distortion level is < 5% at
TEL Line (600
Ω
Load).
5. Input -20dBm/1KHz to Line I/F and measure Receiving level at REV-TEST1
and REV-TEST2.
6. Confirm that the level is -21dBm ± 2dBm and that the distortion level is < 5% at
Receiver. (vol = 2)
IC1, R21, R22,
L9, R93, C11,
R24, R23,
R25, C12,
C95, R94,
C98, C112,
C86, R31,
C108, D4, D5
( T ) SP phone Audio Check
and Confirmation
- 1. Link to Base which is connected to Line Simulator.
2. Set line voltage to 48V and line current to 40mA.
3. Set the handset off-hook using SP-Phone key.
4. Input -25dBm/1KHz to Line I/F and measure Receiving level at SP_TEST1 and
SP_TEST2.
5. Confirm that the level is -14dBm ± 2dBm and that the distortion level is < 5%.
(vol = 3)
IC1, R21, R22,
L9, R93, C11,
R24, R23,
R25, C12,
C39, C101,
C102
Items Check
Point
Procedure Check or
Replace Parts
( A ) Charging Check - 1. Connect Charge Contact 12
Ω
/2W resistor between and charge-.
2. Measure and confirm voltage across the resistor is 3.3V ± 0.2V.
R2, R1
Items Check
Point
Procedure Check or
Replace Parts