Graco Magnum L10 Repair Manual page 21

Specific Problem
Basic electrical problems.
332642C
Cause
Motor overheated.
Electrical outlet is damaged.
Control board leads are
improperly fastened,
improperly mated, or
corroded.
Motor brushes are worn.
Motor armature commutator
damaged.
Fuse is blown.
Motor armature shorting.
Motor armature open circuit.
Control board damaged.
CAUTION: Do not perform
control board diagnostics until
you have determined the
armature is good. A damaged
armature can burn out a good
control board.
Solution
Allow motor to cool for 45 minutes. Retry.
Reset building circuit breaker or replace fuse. Try
another outlet.
Check electric supply with volt meter. Meter must
read 220/240 VAC. If voltage is too high, do not
plug sprayer in until outlet is corrected.
Replace any loose terminals. Make sure all leads
and harnesses are firmly connected.
L30+: Check pressure control harness connection
on front side of drive housing.
Clean control board terminals. Securely reconnect
leads.
Check length of BOTH brushes (brushes do not
wear evenly on both sides of the motor). Brush
length must be 0.25 in. (6.4mm). If brushes are
worn replace motor using Motor Kit. See List of
Kits, page 30.
Check for burn spots, gouges and extreme
roughness. If damaged or if shorts are evident,
replace motor using Motor Kit. See List of Kits,
page 30.
Find cause for blown fuse before replacing. Turn
the motor fan to check for a locked gear or pump.
Use a continuity meter to check for a short to
ground caused by a pinched wire.
L30+: Replace the fuse with correct fuse kit. See
List of Kits, page 30.
M5, L10, M3+, M5+, and L10+: The fuse is not
replaceable. Replace control board. See List of
Kits, page 30.
Check for shorts. See Motor Diagnostics, page
27. If shorts are evident, use Motor Kit to replace
motor. See List of Kits, page 30.
Check motor leads for continuity. If open circuit,
check brushes. Use Motor Kit to replace motor.
See List of Kits, page 30.
See Control Board Diagnostics, page 29.
Replace control board if damaged using Control
Board Kit. See List of Kits, 30.
Advanced Troubleshooting
21