Airless Motor Will Not Shut Off - Graco FinishPro 390 Repair Electrical Manual

Unplug sprayer turn the
prime/spray valve to the prime
position. Plug sprayer in, once
material comes out of the prime
drain hose turn the prime/spray
valve to spray. Does fluid stop
for a moment and then come
though?
YES
Put the sprayer in the prime
position. Remove the control
board cover, turn the sprayer
on and then unplug the
pressure control switch. Does
the motor stop running
YES
Defective pressure
control switch.
Replace.
FinishPro 390
Control Board 261779
Motor will not shut off:
Unplug sprayer turn the
prime/spray valve to the
prime position. Plug sprayer
in, once material comes out
NO
the prime drain hose turn
the prime/spray valve to
spray. Does fluid continue
to flow though the drain
Defective Prime
Spray Valve.
Defective control
NO
board. Replace.
NO
hose?
YES
Replace.
Check the Inlet and Out
valves for a stuck ball,
See freeing up inlet and
outlet check valves. If
ok check the packing
for wear or damage,
replace if needed.
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