Graco LP 555 Operation - Repair - Parts page 32

Troubleshooting
Problem
Sprayer does not run at all
AND
Display shows E=04
OR
Control board status light blinks 4
times repeatedly
Sprayer does not run at all
AND
Display shows E=05
OR
Control board status light blinks 5
times repeatedly
32
What to Check
Check voltage supply to the sprayer
(control board is detecting a multiple
voltage surges).
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.
Locate a good voltage supply to
prevent damage to electronics.
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.Connect a DC voltmeter across the
two motor wires – red & black spin
the motor fan and check for a
voltage to register on the meter. If
voltage is not present, check
brushes. If OK, replace motor. If
voltage is present, go to step 5.
5.Perform a spin test by connecting a
9 –12 Volt battery to the motor
leads. Motor leads may vary in style
and size. Locate the two wires
going to the carbon brushes
normally Red and Black. Motor
should spin when battery is
connected to the motor leads.
BLACK (-)
RED (+)
9-VOLT
BATTERY
YELLOW
ti24722a
3A4203B