47
KX-TG9471B/KX-TG9472B/KX-TGA939T
9.3.2.
Troubleshooting for Speakerphone
When the customer’s telephone line corresponds to the following conditions, and the transmission signal of SP-Phone is
interrupted, performing the next set up to a cordless portable 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 portable address of EEPROM (0129) from 00 to 01 by
Engineering Mode
.
(
P
) SP phone Audio Check
and Confirmation
-
1. Link to Base which is connected to Line Simulator.
2. Set line voltage to 48 V and line current to 40 mA.
3. Set the portable off-hook using SP-Phone key.
4. Input -25 dBm/1KHz to Line I/F and measure Receiving level at SP+ and SP-.
5. Confirm that the level is -14 dBm ± 2 dBm and that the distortion level is < 5%.
(vol = 3)
IC1, R23, C12,
C73, D13,
D14, R152,
C80, L10, L11,
MIC, C11,
C13, RA4,
R27, R28,
R208, R209,
C96, C97,
R215, C72
(
Q
) Charge Pump 2.5V Sup-
ply Confirmation
CP2.5V
1. Confirm that the voltage between testpoint and CP2.5V and GND is 2.5V -0.1/
+0.3V.
C52, C53, C49
(
R
)
Change Pump 4.0V
Supply Confirmation
CP4.0V
1. Confirm that the voltage between testpoint CP4.0V and GND is 4.0V I0.2V.
C50, C51
Items
Check
Point
Procedure
Check or
Replace Parts
