UF-490 (serv.man2) - Panasonic Fax Service Manual (repair manual). Page 100

100

This section explains general troubleshooting procedures for the 400 series of Information Codes. These
errors are primarily caused by poor telephone line quality (loss, noise, echo, etc.). This unit is furnished with
Service Mode 1 to assist in troubleshooting line quality problems.
It is suggested that both the transmitting unit and receiving unit be adjusted. This section gives relevant
parameters in Service Mode 1 for the transmitting and receiving sides. If no improvement is realized after
the parameters are adjusted, it is recommended that the parameters be returned to the default settings.

START

No

Yes

Is this an international 
communication?

#021 : Off

On

#025 : 1st

2nd

#033 : 33600 bps

31200-2400/
TC9600/TC7200

#024 : 2100 Hz

1080 Hz

#030 : 75 ms

1 sec

#010 : -9 dBm

0 to -15 dBm

To improve a poor S/N (signal-to-noise ratio)

#032 : 33600 bps

31200 to 2400 bps

#011 : -43 dBm

-33 dBm or -38 dBm

#033 : 33600 bps

31200 to 2400 bps

#023 : Normal

Long

#013 : 0 dBm

4, 8 or 12 dBm

To equalize loss (Amplitude Distortion) between 
the fax unit and the phone company exchange

#025 : 1st

2nd

#024 : 2100 Hz

1080 Hz

#030 : 75 ms

1 sec

To cope with shifted signal sequences caused by an echo

#070 : 128

256 to 2048

To cope with impulse noise

Perform a communication test after changing settings.

#014 : 0 dBm

4, 8, 12 dBm