Service manual

1-6 Samsung Electronics
PROBLEM ITEMS TO BE CHECKED HOW TO SOLVE
CanÕt copy
CanÕt PRINT
1. Refer to Ôproblems of scanner.Õ
2. Poor quality of printed image : Print
test pattern and check if nozzles have
fallen out.
3. CanÕt print.: Check U17-34, 36 sig-
nals.(LOW ACTIVE)
1. Check centronics cable connection.
2. Is ÔStandbyÕ LED of the system on?
3. Check how print driver has been
installed.
4. Check I/F part of parallel port.
1) Check the initial state of print con-
trol signal of CON8.: No.1, 10 ~14,
31, 32, 36
2) Check input and output signal of
U14.
3) Check input and output signals of
U15-43~51 and U15-53~61.
5. Refer to 2 and 3 of 6-4 ÔPRINGTING
QUALITYÕ.
1. Check CON3(main PBA), main LIU
harness, and P1(LIU PBA).
2. 1) Is external telephone hooked off?
2) Output of U2-4(LIU PBA) is LOW?
3. Check HOOK-OFF. (Line connection):
U17-8(/CML1) is HIGH?
4. Check the signals of U15-122, 123.
5. Check transmission path: Check out-
put of U21-44(main PBA) and input of
U3-3(LIU PBA).
6. Check reception path: Check output
of U3-40(LIU PBA) and input of
U21-45(main PBA).
1. Refer to Ôproblems of scanner.Õ
2. 1) Check contact between ink car-
tridge and the head.: Clean it.
2) Check print control signals of U15-
1~10, U15-158 - 160, U15-12~19,
and U15-21~28. Check input and
output signals of U19,20,23, and
24. Replace the main PBA.
3. Replace the main PBA.
1. Connect it correctly.
2. Press ÔstandbyÕ key to keep the stand-
by mode.
3. Install the print driver again and
reboot the system.
4. Replace the main PBA.
5. Refer to 2 and 3 of 6-4 ÔPRINGTING
QUALITYÕ.
1. Replace defective parts.
2. 1) Hook on external telephone
correctly.
2) If low, replace LIU PBA.
3. If low, replace main PBA. If it is
not hooked off though it is normal,
replace LIU PBA.
4. If the signals of U15-122(LIU_TXD)
are abnormal, replace main PBA. If
the signals of U15-123(LIU_RXD) are
abnormal, replace LIU PBA.
5. If it is abnormal, replace main PBA.
6. If the output of U3-40(LIU PBA) is
not confirmed, replace LIU PBA. If
the output of U3-40(LIU PBA) is con-
firmed but the input of U21-45(main
PBA) is not confirmed, check the
circuit around U6(main PBA).
Defective
Transmission
/ Reception
In case
PC
controls