Radio Shack TRS-80 Service Manual page 64

0
0
:J
0
.-
(J)
Q)
(I)
-
- ;;J"
(ii .
'1J
0
,,
~
I
Phenomen
3
-9- Character I
misalignment
Condition
Origin position differs
af'ter making many
reciproca. I movement in
Y-diroetlon. Origin
position ch>nges af'ter
printing a large number
of characters.
"f"
I• drawn as shown
below.
f
Cause
4
Low battery voltage,
1
Ru~ber
roller and paper
slip.
2
Deformation of paper
guide.
3 Roll paper is guid ed
improperly.
4
Paper type does not
match printer.
I Improper engagement of
robbin gear unit (2·3)
after sliding by one
tooth.
2 Rolary holder and slider
do no! lock sufficiently.
3 Nay between pen return
spring and pen t ips.
4
Wire spring fatigue in wire
unit (2-4), elonga. t ion or
wire.
Location and Method
of Checking
Check if battery voltage is
below 4,SV,
Check for stained rubber roller.
Check paper guide.
Check roll paper rotation and
ensure that the center of the
paper and the center o r the
...£.rinter are aligned.
Check that the specified paper
is
UM:d .
Check gear engagement.
Check rotary holder play by
rotating it slowly by hand.
Check by rolating X·bobbln
gear back and fortl1 for several
seconds by hand in the pen·
down mode.
Check for slack in wire spring.
Repair Method
Recharge to regular voltage.
Wipe off rubber rollers stain.
• Repair inper guide if there
is any deformation.
• Repair roll paper guide.
Repair roll paper guide.
Use the specified paper.
Mount properly.
Exchange slider unit.
Replace rolary ho 1aer.
Replace wire unit.
)>
Q)
::>
0.
3
0
iD
Q)
O'
0
c:
-
e n
::T
Q)
-a
-0
()
'
~
(,;\
0
0
Q)
-
: :T
:::::
"O
r
-0
0
'
~
(,;\
0
0
5 ·
0