User guide

40 Troubleshooting
Table 6-1 Troubleshooting (continued)
Symptom Possible Cause Recovery
Fluid leaks through the
Extension Seat, or poor dot
quality (dots not breaking off
from nozzle).
Air Piston/Locking Nut positioned
too low
Use the piston height gage tool to ensure
correct position. See the Maintenance and
Service section.
Seat Extension is frequently
damaged or poor dot quality
(dots not breaking off from
nozzle).
Air Piston/Locking Nut positioned
too high
Use the piston height gage tool to ensure
correct position. See the Maintenance and
Service section.
U-cup seal in lower body wears
out prematurely or frequently
during Silver Filled or abrasive
fluid applications.
Wrong color (yellow) U-cup installed
Change to a gray color U-cup seal. See the
Appendix for part number.
Oval/tear-shaped dots
(in one direction)
Loose nozzle
Tighten the nozzle with a 4 in-lbs. torque
wrench.
Damaged nozzle tip (bent or
broken)
Check the nozzle tip using magnifying glass.
If broken or bent, replace with a new one.
Nozzle may be bowed (too tight)
Remove the nozzle from valve and, without
cleaning the nozzle, look inside the threaded
portion. If adhesive has bled out, or spread
beyond the seat inner diameter, or appears
as a spiral or web pattern, the nozzle is
bowed and needs to be replaced.
Oval dots (in various directions)
Micro-Adjustment setting too low
Verify that micro-adjustment setting is
correct. Increase in 0.2-mm increments, if
necessary.
Dispense gap too high
Check dispense gap in Fluidmove Dot
Parameters and adjust if needed.
Dirty nozzle Clean the nozzle with solvent.
Damaged or worn seal Replace the upper body seal.
Damaged or bent needle Replace the needle and seat extension.
Uneven dots Nozzle may be bowed (too tight)
Replace the nozzle and check that it is not
over-tightened.
Satellite dots
Temperature may be too high
Check temperature and if necessary, lower
in increments of 2° C (3.6° F).
Dispense gap may be too high
1. Check dispense gap in Fluidmove Dot
Parameters and adjust if needed.
2. Repeat needle-to-height sensor Z-offset
in Fluidmove.
Nozzle may be dirty or capped over
1. Clean the nozzle with solvent.
2. Increase purge frequency.
Preload Spring may be too high Adjust, if needed, to reduce spring tension.
Damaged or bent needle Replace the needle and seat extension.
Dots are stringing or stitching
Dirty nozzle Clean the nozzle with solvent.
Dispense gap too low
Verify that the dispense gap is set to the
appropriate height in Fluidmove Dot
Parameters
. Adjust if necessary.
Incorrect temperature
Set the correct temperature. Refer to the
Fluidmove User Guide or Online Help.
Damaged nozzle Replace the nozzle.
Preload is set too low Verify and adjust the preload.