Panasonic UF-890 Service Manual page 152

4.6.2 Poor Transmitted Copy Quality
START
Make a copy.
Is the printed copy normal?
Yes
Perform a transmission test
to a reference fax unit.
Is the transmitted copy
normal?
Yes
Does poor transmitted copy
appear when transmitting to
a specific receiver?
Yes
The receiving unit may be
defective.
END
No
Is the LED Array lit?
Yes
Are CN5 (FCB PCB) and
CN30 (CCD PCB)
connected properly?
Yes
1. Replace the Scanner
Block.
2. Replace the FCB PCB.
No
1. Check CN3 (FCB PCB)
and CN25 (LCU PCB).
2. Check the telephone cord.
Replace if necessary.
No
Telephone line quality is
poor.
No
Does CN 9, pins 1 and 2, of
the FCB PCB measure +24 VDC?
(Pin 2 is not used for UF-890)
Yes
Does LEDD go Low when
the scan starts?
Yes
Check CN 9 on the FCB
PCB and the LED harness.
Does the problem still
occur?
Yes
Replace the LED Array.
No
Connect them correctly.
152
No
Replace the LVPS (POW).
No
Replace the FCB PCB.