DOWNLOAD Panasonic UF-490 / UF-4000 / UF-4100 Service Manual ↓ Size: 16.03 MB | Pages: 127 in PDF or view online for FREE

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No

Is the Control Panel Unit locked?

Close the Control Panel Unit firmly.

Yes

No

Is the ADF Roller clean?

Clean the surface of the roller
with isopropyl alcohol (Sect. 2.2.2)

Yes

No

Is the ADF Roller worn out?

Replace the ADF Roller
(Sect. 2.2.5).

Yes

No

Does the ADF Roller drive 
properly?

Does the ADF Roller's gear
system function properly?

Yes

No

Separation Rubber  normal?

Is the adjustment of the

Is the Separation Rubber worn
out?

Replace the Separation Rubber.

No

Clean or adjust the Separation
Rubber Pressure.

No

Yes

Adjust the gear system or replace
defective parts.

Yes

Yes

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Close the Control Panel Unit 
firmly.

No

No

No

No

No

No

Yes

Yes

Yes

Yes

Yes

Yes

Is the Control Panel Unit
closed?

Close the Green Latch Hooks 
firmly.

Is the Green Latch Hooks 
locked on the Scanning 
Roller Assy?

Clean or replace PNL PCB.

Do all sensors on the PNL
PCB operate normally?

Clean the surface of roller 
with isopropyl alcohol
(Sect.2.2.2).

Does the Feed Roller have 
drive and sufficient friction?

Remove the foreign particles 
or papers from the document 
path.

Is the document path clear
of foreign particles or paper?

Adjust or replace any 
defective parts.

Is the Transmitting 
mechanism operating 
properly?

107

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.

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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

108

Make a copy.

Is the printed copy 
normal?

Is the transmitted 
copy normal?

The receiving unit 
may be defective.

Telephone line quality
is poor.

Is the CIS LED 
lit?

Replace the Low 
Voltage Power 
Supply Unit.

Replace the SC 
PCB.

Replace the CIS.

Connect it correctly.

Does CN3, pin 7 on 
SC PCB measure 
+24 VDC?

Does CN3, pin 6 
measure 0V when 
the scan starts?

Is CN3 on the 
SC PCB
connected properly?

Perform a transmission 
test to a reference 
fax unit.

Does poor transmitted
copy appear only 
when transmitting to a 
specific receiver?

(1) Replace the CIS.
(2) Replace the SC PCB. 

Check the Telephone Line Cable.
Replace the SC PCB.

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

No

No

No

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