Graco A Series Instructions-Parts List Manual page 14

Basic Problem Solving (continued)
TYPE OF PROBLEM
Mechanical (continued)
Electrical
Troubleshooting
WHAT TO CHECK
If check is OK, go to next check
2. Check pump connecting rod pin (17). It must be
completely pushed into connecting rod (15),
and retaining spring (18) must be firmly in con-
necting rod groove. See page 23.
3. Check for motor damage. Remove drive hous-
ing assembly (11). See page 28. Try to rotate
motor fan by hand.
1. Check electrical supply with volt meter. Meter
should read 90–110 VAC.
2. Check extension cord for visible damage. Use
a volt meter or test lamp at extension cord out-
let to check.
3. Check sprayer power supply cord (57) for
visible damage such as broken insulation or
wires.
4. Check motor brushes for the following:
a. Loose terminal screws.
b. Broken or misaligned brush springs.
c. Brushes binding in holders.
d. Broken leads.
e. Worn brushes.
NOTE: The brushes do not wear at same rate on
both sides of motor. Check both brushes.
5. Check motor armature commutator for
burn spots, gouges and extreme roughness.
Remove motor cover and brush inspection
plates to check. See page 20.
6. Check motor armature for shorts
using armature tester (growler) or perform
motor test. See page 19.
7. Check leads from pressure control and motor to
motor start board (47) to be sure they are se-
curely fastened and properly mated.
8. Check motor start board (47) by substituting
with a good board. See page 27.
CAUTION: Do not perform this check until mo-
tor armature is determined to be good. A bad
motor armature can burn out a good board.
9. Check power supply cord (57). Disconnect
cord from inlet filter (51). Connect voltmeter
to cord's receptacle and plug into wall
outlet. Meter should read 90–110 VAC. Unplug
sprayer.
10. Check inlet filter (51). Disconnect black and
white power inlet filter terminals;
connect volt meter to these leads. Plug in
sprayer. Meter should read 90–110 VAC. Un-
plug sprayer.
WHAT TO DO
When check is not OK, refer to this column
2. Push pin into place and secure with
spring retainer.
3. Replace motor (4) if fan won't turn. See
page 26.
1. Reset building circuit breaker; replace
building fuse. Try another outlet.
2. Replace extension cord.
3. Replace power supply cord.
4. Refer to page 20.
a. Tighten.
b. Replace broken spring and/or align
spring with brush
c. Clean brush holders. Remove
carbon with small cleaning brush.
d. Replace brushes
e. Replace brushes if less than 10 mm
long.
5. Remove motor and have motor shop
resurface commutator if possible. See
page 26.
6. Replace motor. See page 26.
7. Replace loose terminals; crimp to leads.
Be sure male terminal blades are straight
and firmly connected to mating part.
8. Replace board. See page 27.
9. Replace power supply cord.
10. Replace inlet filter.