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[PHENOMENON | CONDITION
| =
CAUSE _| LEVEL | CHECK POINT AND METHOD
REPAIR METHOD
3. The motor
(2) The paper
No Timing signals
@
Check if termina! voltage
|@ Check if the timing detec-
doesn't stop
has been fed | are generated
from the power supply is
tor ass''y is mounted
in
rotating
-
but motor ro-
being supplied.
the correct position.
tation
Voltage: 5 to 15 V
If not, replace the timing
doesn't stop
@
If not, replace the timing
detector ass'y.
detector ass'y
@
If not, adjust the mount-
@
Use a galvanometer to
ing position of the timing
check is current is flow-
detector ass'y
(see sec-
ing to the timing detector
tion 3.3, eioneal
ass'y.
@
Check if the LED is emit-
ting light.
Check if there is conduc-
tivity between the com-
mon pattern terminals of
the character selective
magnets.
If not, perform resolder-
ing or replace the charac-
ter selective magnet unit.
(1) Damaged com-
mon pattern in
the character
selective mag-
nets and faulty
soldering
Faulty or im-
properly mount-
ed timing detec-
tor ass'y
improperly
mounted char-
acter selective
magnet unit
4. No printing in | The motor ro-
any columns | tates normally,
but no printing
is performed
See CAUSE (2) of PHENOMENON
3.
@
If not, adjust the mount-
ing position
(see section
3.2.2
|Main Assembly
B).
If not, perform resolder-
ing or replace the charac-
ter selective magnet unit.
Check if the side dowels
on the character selective
unit fit securely into the
grooves in the frame unit.
Check if there is conduc-
tivity between the com-
mon terminals of the per-
tinent character selective
magnet.
Damaged
line
in the pattern of
the correspond-
ing character
selective mag-
net or faulty
soldering
(2) Damaged line
B
in a coil in the
character sekec-
tive magnet unit
5. Consistently
missing
characters
Printing is not
performed only
in specific
columns
Check if the coil resis-
tance of the pertinent
character selective mag-
net unit is within rated
values.
D.C. resistance:
25 9 + 10 Q (at 25°C)
Check if the typewheel
guide is properly mount-
If not, replace the charac-
ter selective magnet unit.
If improperly mounted,
re-mount it correctly.
The printing
wheel guide is
improperly
ed and if the tooth corre-
see section 3.2.2
mounted or has
sponding to the missing
broken/bent
column is broken or bent. | @
If any teeth are broken or
teeth
bent, replace the printing
wheel guide.
If not rated or if no input
trigger pulses are being
generated, repair the
drive control circuit.
Faulty input
trigger pulse
Use an oscilloscope to
check if the input trigger
pulse for the pertinent
column
is within rated
values.
(5) improperly
mounted char-
acter selective
magnet unit
(1) Malfunction of
the print
mechanism
{2} The motor
speed is too
fast
See CAUSE (3) of PHENOMENON
4.
@
If not, replace the charac-
ter selective magnet unit.
Check if the character se-
lective paw! operates
smoothly.
@
Use a tester or oscillo-
scope to check if the
Timing pulse from the
wiring board are within
the rated pulse width.
6. Intermittently
| Missing charac-
missing
ters occur
characters
sporadically
Missing charac-
ters occur
sporadically
B
B
@ if not, replace the motor
(3) Faulty input
@
See CAUSE (4) of PHENOMENON
5.
trigger
pulses
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