Graco 231-033 Instructions-Parts List Manual page 19

LOW OUTPUT
TYPE OF PROBLEM
Low Output
WHAT TO CHECK
If check is OK, go to next check
1. Check for worn spray tip.
2. Check to see that pump does not continue to
stroke when gun trigger is released. Plug in
and turn on sprayer. Prime with paint. Trigger
gun momentarily, then release and engage
safety latch. Relieve pressure, turn off and un-
plug sprayer.
3. Check electrical supply with volt meter. Meter
should read 105–125 VAC.
4. Check extension cord size and length; must
be at least 12 gauge wire and no longer than
150 ft.
5. Check G1 and G2 leads from bridge (308) to
circuit board (71) for damaged or loose wires
or connectors. Refer to Fig 27–1.
6. Check stall pressure. Refer to Pressure Con-
trol Adjustment on page 30.
7. Check bridge (308) + and – leads and termi-
nals to motor. Inspect wiring insulation and ter-
minals for signs of overheating. See page 27.
8. Check for loose motor brush leads and termi-
nals. See page 25.
9. Check for worn motor brushes which should
be 1/2" minimum. See page 25.
10.Check for broken and misaligned motor brush
springs. Rolled portion of spring must rest
squarely on top of brush.
11. Check motor brushes for
holders. See page 25.
12.Check circuit board (71) by substituting with a
good circuit board. See page 28.
13.Check motor armature for shorts by using an
armature tester (growler) or perform spin test.
See page 22.
14. Check bridge (308) by substituting with a
good bridge or by performing the bridge test.
See page 23 or 27.
CAUTION: Do not perform this check until
armature is determined to be good. A bad ar-
mature will immediately burn out a good
bridge.
WHAT TO DO
When check is not OK refer to this column
1. Follow Pressure Relief Procedure Warn-
ing then replace tip. See your separate gun
or tip manual.
2. Service pump. See pages 36–38.
3. Reset building circuit breaker; replace
building fuse. Repair electrical outlet or try
another outlet.
4. Replace with a correct, grounded exten-
sion cord.
5. Clean circuit board male terminals. Re-
place loose or defective lead terminals. Se-
curely reconnect lead terminals to board.
6. Perform pressure control adjustment. See
page 30.
7. Be sure male terminal blades are centered
and firmly connected to female terminals.
Replace any loose terminal or damaged
wiring. Securely reconnect wires to bridge.
8. Tighten terminal screws. Replace brushes
if leads are damaged. See page 25.
9. Replace brushes. See page 25.
10.Replace spring if broken. Realign spring
with brush. See page 25.
binding in brush 11. Clean brush holders, remove carbon dust
with small cleaning brush. Align brush lead
with slot in brush holder to assure free verti-
cal brush movement.
12.Replace circuit board. See page 28.
13.Replace motor. See page 34.
14.Replace bridge. See page 27.