Read Panasonic UF-490 (serv.man2) Service Manual online
101
4.6.2.
Poor Transmitted Copy Quality
Make a copy.
Is the printed copy
normal?
normal?
Is the transmitted
copy normal?
copy normal?
The receiving unit
may be defective.
may be defective.
Telephone line quality
is poor.
is poor.
Is the CIS LED
lit?
lit?
Replace the Low
Voltage Power
Supply Unit.
Voltage Power
Supply Unit.
Replace the SC
PCB.
PCB.
Replace the CIS.
Connect it correctly.
Does CN3, pin 7 on
SC PCB measure
+24 VDC?
SC PCB measure
+24 VDC?
Does CN3, pin 6
measure 0V when
the scan starts?
measure 0V when
the scan starts?
Is CN3 on the
SC PCB
connected properly?
SC PCB
connected properly?
Perform a transmission
test to a reference
fax unit.
test to a reference
fax unit.
Does poor transmitted
copy appear only
when transmitting to a
specific receiver?
copy appear only
when transmitting to a
specific receiver?
(1) Replace the CIS.
(2) Replace the SC PCB.
(2) Replace the SC PCB.
Check the Telephone Line Cable.
Replace the SC PCB.
Replace the SC PCB.
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
START
END
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