Service manual

Troubleshooting
Samsung Electronics 4-17
4-6-2 FAX(only SCX-5315F)
4-6-2-1 FAX/TELEPHONE Precautions
PROBLEM ITEMS TO BE CHECKED. HOW TO SOLVE
TEL LINE CANNOT BE
ENGAGED
(NO DIAL TONE)
• When you press “ OHD” key:
a) Check line cord connection.
b) Check MAIN LIU harness, and CN1
(LIU PBA).
c )Check relay operation of LIU PBA :
Is the control signal of CN18(main) low?
a) insert it correctly into the connection
jack called “line”.
b) Replace defective parts.
c) Replace main PBA IF the control signal
of CN18(main) is high.
Replace LIU PBA if high but phone line
cannot be connected.
Cannot MF dial • Check CN18 (main PBA), MAIN-LIU
harness, and CN1 (LIU PBA)
• Replace defective parts.
MF dial is possible but
not DP dial.
• Check DP control signal of CN18-11 of
MAIN PBA and the circuit around R15. U6
and Q2 of Liu PBA.
• Replace LIU PBA.
Defective fax transmis-
sion
• Check CN18 (main PBA), MAIN LIU
harness, and CN1(LIU PBA).
• Is the external phone hooked off?
• Check ‘hook off’ : Refer to ‘TEL LINE
CANNOT BE ENGAGED’ above.
• Check transmission path : Check output of
CN20-3.4 and T2-4(LIU PBA).
• Check reception path : Check output CN1-
1 (LIU PBA) and input of CN18-1
(main PBA).
• Replace defective parts.
• Replace LIU PBA if low.
• Refer to ‘TEL LINE CANNOT BE
ENGAGED’ above.
• Replace main PBA, if abnormal.
• Replace LIU PBA if CN1-1(LIU PBA) is not
confirmed.
Replace main PBA if CN20-1(MAIN PBA)
is not confirmed.
Defective automatic fax
reception
• Is the ring checked?
Check ring pattern at CN1-9 (LIU PBA).
• Refer to ‘Defective Transmission.’
• Replace LIU PBA if it cannot be checked.
• Refer to ‘Defective Transmission’.