Panasonic KX-TG8421EB Service Manual page 55

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 inter-
rupted, 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 handset address of EEPROM (0129) from 00 to 01 by Engineering Mode.
KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E
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