Commodore MPS-801 - Page 16

TROUBLESHOOTING GUIDE (Continued)
SYMPTOM 3. The carrier unit moves, but there is no printing.
POSSIBLE CAUSE SOLUTIONS
1. The print head is defective.
With meter set at 200 ohm range, a
reading
of about 3.5 to 4 ohms of
t'~~~~~
resistance should be measured between
1
pins 1 and 2 .
2
. ~
MG
.~
Replace print head if defective.
2. Control PCB is defective. Check the output of PIN. Repair it.
MN£1l-
210 or 250us
SYMPTOM 4. Some part of a printed character is missing.
POSSIBLE CAUSE
SOLUTIONS
1. Part of the platen ridge is broken.
Replace
the platen.
2. Control PCB is defective. Repair it.
3. The position of the dot sensor is not Adjust it.
correct.
SYMPTOM 5. Printing is too light.
POSSIBLE CAUSE SOLUTIONS
1.
Ribbon clutch spring is broken.
Replace it.
(Ribbon
shaft does not revolve to re-ink
the ribbon.)
2. Inker in the ribbon cassette is not Reinstall or replace the inker.
correctly installed.
3.
Print head is defective. Replace it.
13