DeVilbiss JGA PRO Series Technical Bulletin page 16

Troubleshooting Possible Problems in Operation (cont)
Starved spray pattern
Excessive overspray
Dry spray
Fluid leaking from
packing nut
Fluid leaking or dripping
from front of gun
Runs and sags
Inadequate material flow
Blocked vent in Cup lid
Low atomisation air pressure
Air pressure to high.
Gun too far from work surface.
Air pressure too high.
Gun too far from work surface.
Gun motion too fast.
Fluid flow too low.
Packing or Fluid Needle worn.
Fluid nozzle or fluid needle worn or
damaged.
Foreign matter in fluid nozzle.
Fluid needle dirty or stuck in needle
packing
Wrong size fluid needle or fluid
nozzle.
Too much material flow.
Material too thin.
Gun tilted on an angle, or gun
motion too slow.
16
Wind fluid adjusting knob out or
change to larger fluid nozzle size
Clean lid and unblock vent
Increase air pressure and
rebalance gun.
Reduce air pressure.
Adjust to correct distance.
Reduce air pressure.
Adjust to correct distance.
Slow down.
Wind out needle adjusting screw or
use larger nozzle size.
Replace.
Replace fluid nozzle and fluid
needle.
Clean.
Clean
Replace fluid nozzle and fluid
needle.
Turn fluid adjusting knob clockwise
or switch to smaller fluid nozzle
and fluid needle size.
Mix correctly or apply light coats.
Hold gun at right angle to work and
adapt to correct gun technique.
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