Radio Shack TRS-80 Service Manual page 62

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Phenontcn
-6- Does not select
proper color
- 7- Paper is not
fed.
Condition
I
It Is reproduced no
1natte:r how rnany ti.mes
power
1upply
Is turned
on.
2
A different color
is
selected when the powtr
supply Is turned on again
and reset.
3
Rotary holder rotations
arc short by one rccipro·
cation when the power is
turned on.
I Y motor (3-1) does not
rotate .
Cause
I
Pen inounting position
is different.
I
1nsufficicnt magnetic
force.
2
Reed switch
is
faulty
I
Discrepancy in mounting
of the reed switch unit.
2
Exccs.si.,·c rotation of
rotary holder.
I
Y Motor Jeod wile
is
cut.
2 Deformation ofY·gear
idle (3-2).
3
Rubber roller unit (3·3)
does not rotate
wen.
4
Foreign matter between
gears.
5
Low battery voltage.
Location and Method
of Checking
Check that the proper colored
pen is mounted using :is
reference the position when
the color position detection
magnet
is
located at the left
side.
Check the magnetic Hux on
the magnet surface with a
Gauss meter.
Check if reed switch aetuotes
when magnetic flux is nonnal.
Check position of reed switch
unit.
Check if rot. a ry holder rotates
exccs.sively due to foreign
matler, etc.
Check if normal current i. s
in1pressed lo each phase
or
the motor.
Check if Y.gear Ide! is nonnal
or not.
Dismount Y·gear idle and check
rubber roller rotations.
Caution rotations are heavy due
to friction between rubber
roller and paper guide when
paper is not inserted.
Slowly rotate Y-gear idle by
hand and check for foreign
mat ter.
Check if battery voltage
is below 4,SV,
Repair Method
Rent pen Jn Its proper position.
Replace rotary holder.
Replace reed switch unit (4-6).
Replaoe reed switch unit.
Remo"·eToreign
ma1tcr,
etc.
Replace X·motor.
Replace Y .gear Idle.
Replace rubber roller unit.
Remove foreign matter.
Recharge to norntal voltage.
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