Radio Shack TRS-80 Service Manual page 60

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Phenomen
Condition
2 ElecHomagnet operate
normally
Cau- s e
2
Abnormally large
electromagnet
.
suction stroke
.
J Low battery "oltage
4
Electromagnet unit is
faulty.
5 Rotary holder on slider
unit has mo\'ed.
6 Ejection le .. ·er does not
operate smoothly.
I
Pen movement is slow
2
Defonnat ion and fatigue
of pen return spring
3 Paper is not win ding
on rubber roller
properly
4
Pen is too long
Location and Method
of Checking
Check if gap between rubber
roller and pen tip is 0.6mm in
the pen.up mode
Check if battery voltage
is below 4.SV.
Check operation of the
actuator for the electromagnet
unit, spring fatigue, deform•·
tion etc.
Check that rotary holder pen is
directly above the specified
position (print position).
Check for a bend in the
ejection lever and inspect the
bearing section.
Check the shape of the pen.
Also check for rolary holder
deformat ion and Ute presence
of fo reign matter.
Inspect the pen return spring.
Remove paper and check for
paper guide defonnation, etc.
Measure the pen length.
Repair Method
• Rcpl•ce with a pen having
the standard length
+0
(23.3 - O. lmm) .
• Adjust the gap by turning
the mounting screw on the
electrom~et
uni!J.4·!1
Recharge 10 normal voltage.
Replace electromagnet unit.
)danually maintain electro-
magnet actuator in the
3dsorption state, rotate rotary
holder in a counterclockwise
direction, 3.nd fix it in its
...f!~~sition.
• Exchange ejection lever and
ejection leve r shaft unlt.
• Pen exchange
• Rotary holder exchange
• Removal of foreign matter
Replace slider head unit (4·5)
• Return 1110 ils normal
shape using tweezers, etc
if
it Is only slightly defom1ed.
• Remount properly if small
roller which holds the paper
hucome off.
• Moun1 a proper pen
(length
23.JjJlllll)
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