Graco FinishPro 311911C Repair Manual page 9

Problem
Basic Electrical
See wiring diagram, page 36
311911C
What To Check
(If check is OK, go to next check)
1. Electric supply. Meter must read
105-130 Vac for 110-120 Vac models
and 210-255 Vac for 230 Vac mod-
els.
2. Extension cord. Check extension
cord continuity with volt meter.
3. Sprayer power supply cord. Inspect
for damage such as broken insula-
tion or wires.
4. Fuse (FinishPro 390). Check
replaceable fuse on control board
(next to ON/OFF switch).
5. Motor leads are securely fastened
and properly connected to control
board.
6. Motor thermal switch. Yellow motor
leads must have continuity through
thermal switch.
7. Brush cap missing or loose brush
lead connections.
8. Brush length which must be 1/4 in.
(6mm) minimum.
NOTE: Brushes do not wear at the
same rate on both sides of motor.
Check both brushes.
9. Motor armature commutator for burn
spots, gouges and extreme rough-
ness.
10. Motor armature for shorts using
armature tester (growler) or perform
spin test, page 16.
11. Pressure control not plugged in to
control board.
What To Do
(When check is not OK, refer to this column)
Reset building circuit breaker, replace building fuses.
Try another outlet.
Replace extension cord. Use shorter extension cord.
Replace power supply cord. See page 21, Power
Cord Replacement.
Replace fuse after completing motor inspection. See
page 23, Fuse Replacement.
Replace loose terminals; crimp to leads. Be sure ter-
minals are firmly connected.
Clean circuit board terminals. Securely reconnect
leads.
Replace motor. See page 34, Motor Replacement.
Install brush cap or replace brushes if leads are dam-
aged. See page 18, Motor Brush Replacement.
Replace brushes. See page 18, Motor Brush
Replacement.
Remove motor and have motor shop resurface com-
mutator if possible. See page 34, Motor Replace-
ment.
Replace motor. See page 34, Motor Replacement.
Insert pressure control connector into control board.
Troubleshooting
9