Graco Ultra MAX II 490 PC Pro Operation, Parts page 32

Troubleshooting
Problem
Sprayer does not run at all
AND
Control board status light blinks 3
times repeatedly
Sprayer does not run at all
AND
Control board status light blinks 5
times repeatedly
32
What to Check
Check transducer or transducer
connections (control board is not
detecting a pressure signal).
Control is commanding motor to run
but motor shaft does not rotate.
Possibly locked rotor condition, an
open connection exists between
motor and control, there is a problem
with motor or control board, or motor
amp draw is excessive.
How to check
Turn ON/OFF switch OFF and
disconnect power to sprayer.
Check transducer and connections to
control board.
Disconnect transducer from control
board socket. Check to see if
transducer and control board contacts
are clean and secure.
Reconnect transducer to control
board socket. Connect power, turn
ON/OFF switch ON and control knob
to 1/2 turn clockwise. If sprayer does
not run, turn ON/OFF switch OFF and
go to next step.
Connect a confirmed working
transducer to control board socket.
Turn ON/OFF switch ON and control
knob to 1/2 turn clockwise. If sprayer
runs, install new transducer. Replace
control board if sprayer does not run.
Check transducer resistance with an
ohmmeter (less than 9k ohm between
red and black wires and 3-6k ohm
between green and yellow wires).
1.Remove pump and try to run
sprayer. If motor runs, check for
locked or frozen pump or drive train.
If sprayer does not run, continue to
step 2.
2.Turn ON/OFF switch OFF and
disconnect power to sprayer.
3.Disconnect motor connector(s) from
control board socket(s). Check that
motor connector and control board
contacts are clean and secure. If
contacts are clean and secure,
continue to step 4.
4.Set sprayer to OFF and spin motor
fan 1/2 turn. Restart sprayer. If
sprayer runs replace control board.
If sprayer does not run, continue to
step 5.
3A6491E