Overall Weak Printout; Overall Too Strong Printout (Bleeding); Weak Or Missing Printout Of Some Dots - UBI EasyCoder 501 Service Manual

UBI EasyCoder 501 – Service Manual
26. TROUBLE SHOOTING, cont'd.
26.3
Printing Troubles, cont'd.
Example of normal printout.
Example of bleeding.

Overall weak printout

• Check as for "No printout at all".
• Check Contrast setup in Setup Mode for extreme value.
• Verify that the print media matches the option selected in the
Setup Mode.
• Correct voltage for the printhead? Measure voltages V24 and
P24, see chapter 17.7.
• Incorrect longitudinal adjustment of the printhead? See further
chapter 24.3.

Overall too strong printout (bleeding)

Too strong a printout is particularly troublesome when printing
compact bar codes, in which case spaces between the bars become
less distinctive, and consequently less readable.
• Check Contrast setup in Setup Mode for extreme value.
• Are you using a paper stock and/or transfer ribbon of approved
quality for the selected type of printing?
• Check the voltage for the printhead (P24) as explained above
under "Overall weak printout".

Weak or missing printout of some dots

• Examine the printhead and the pressing roller for dust, adhesive
residue, or damage. Clean or replace.
• One or two missing dots may be due to mechanical damage to the
printhead. Try to establish why such damage have occurred in
order to prevent future failures of this kind. (Hard foreign
particles, electrostatic discharge?).
If the printer has been used for printing on less than full width
labels for some time, the pressing roller and possibly also the
printhead may have become worn from the outer paper edge. This
will show up when reverting to wider labels. Change the pressing
roller and possibly also the printhead.
• Check if any preprinted ink has got stuck to the dot row. Avoid
preprinted labels with ink that has a low melting point (less than
+225°C).
• If many dots, or a block of dots, are missing, the internal IC circuit
of the printhead is probably damaged. Replace the printhead.
• Circuit IC-700 generates all signals to the thermal printhead.
Therefore, unexpected printouts or strange patterns could appear
if IC-700 has been damaged.
Continued!
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