Commodore MPS-801 - Troubleshooting Guide

TROUBLESHOOTING GUIDE
SYMPTOM 1. The POWER lamp does not light.
POSSIBLE CAUSE SOLUTIONS
1 . Fuse is blown (F1). Replace only with a fuse of the same
rating
2. Power
switch is broken. Replace it
3.
Transformer is bad. Remove ribbon cable from CN6 and
CARE FULL
Y check the secondary output
of the transformer. With a meter set on
200 VAC, you should read
approximately:
25 VAC between pins 2 and 3
10 V AC between pins 4 and 5
16 VAC between pins 1 and 6
SYMPTOM 2. The carrier unit does not move or movement is too slow or too fast.
POSSIBLE CAUSE
SOLUTIONS
1.
Recovery spring is broken.
Replace it.
2.
H solenoid is defective.
To check H solenoid, remove cable at
connector CN 4. Take an ohmmeter
reading between pins 1 and 2. Approx-
imately 63 ohms resistance should be
present.
3.
Timing belt is broken.
Replace it.
4.
Motor does not revolve.
To
check carriage motor, remove cable at
connector CN 4. Take an ohmmeter
reading between pins 2 and 3. Approx-
imately 28 ohms resistance should be
present.
If motor resistance is good,
check
control PCB.
5. Guide pillar B is
not oiled.
Lubricate
with the designated oil.
6. The position
of the idler pulley is not The idler pulley sits just above the
correct.
recovery spring and can be adjusted (see
Section 5
of Mechanical Assembly).
7. The print head position is too near to the Readjust the position.
platen.
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