15
TYPE OF PROBLEM
WHAT TO CHECK
If check is OK, go to next check
WHAT TO DO
When check is not OK refer to this column
1
. Check leads from bridge (308) to motor to be
sure they are securely fastened and properly
mated.
1. Replace loose terminals; crimp to leads.
Be sure male terminal blades are straight
and firmly connected to mating part.
2. Check G1 and G2 connections between cir-
cuit board (79) and bridge (308) for damage
or loose terminals.
2. Clean circuit board male terminals. Re-
place loose or damaged terminals. Se-
curely reconnect leads.
3. Check for loose motor brush lead connec-
tions and terminals. See page 23.
3. Tighten terminal screws. Replace brushes
if leads are damaged. See page 23.
4. Check brush length which should be 1/2”
minimum. See page 23.
NOTE:
The brushes do not wear at the same
rate on both sides of the motor. Check both
brushes.
4. Replace brushes. See page 23.
5. Check for broken or misaligned motor brush
springs. Rolled portion of spring must rest
squarely on top of brush. See page 23.
5. Replace spring if broken. Realign spring
with brush. See page 23.
6. Check motor brushes for binding in brush
holders. See page 23.
6. Clean brush holders. Remove carbon with
small cleaning brush. Align brush leads
with slot in brush holder to assure free ver-
tical brush movement.
7. Check motor armature commutator for burn
spots, gouges and extreme roughness. Re-
move motor cover and brush inspection
plates to check. See page 23.
7. Remove motor and have motor shop resur-
face commutator if possible. See page 32.
8. Check motor armature for shorts using arma-
ture tester (growler) or perform spin test. See
page 20.
8. Replace motor. See page 32.
9. Check bridge (308) by substituting with a
good bridge or performing bridge test. See
page 21.
CAUTION:
Do not perform this check until
motor armature is determined to be good. A
bad motor armature will immediately burn out
a good bridge.
9. Replace bridge. See page 25.
Condition B
(continued)
Both lamps off
1. Check circuit breaker (309) button to be sure
it has not popped up.
1. Depress button to reset. If circuit breaker or
fuse continues to open, see “Electrical
Short”, page 19.
REFER TO THE WIRING
DIAGRAM ON PAGE 185
TO IDENTIFY TP POINTS.
2. Check power supply cord (31 1). Disconnect
TP6 female (neutral) and TP1 female and
connect volt meter to these leads. Plug in
sprayer. Meter should read 105 to 125 VAC.
Unplug sprayer. Reconnect TP1.
2. Replace power supply cord. See page 24.
NOTE:
Connect the volt meter
to the terminal not the wire
which you disconnect from the
terminal.
3. Check ON/OFF switch (303). Disconnect
TP2 and connect volt meter to TP6 female
and TP2 male. Plug in sprayer and turn
ON
.
Meter should read 105 to 125 V AC. Turn off
and unplug sprayer. Reconnect TP2.
3. Replace ON/OFF switch. See page 24.
4. Check jumper wire (306). Disconnect TP3
and connect volt meter to TP6 female and
TP3 female. Plug in sprayer and turn on. Me-
ter should read 105 to 125 VAC. Turn off and
unplug sprayer. Reconnect TP3.
4. Replace jumper wire. See page 26.
5. Check circuit breaker (309). Connect volt me-
ter to TP6 female and TP4. Plug in sprayer
and turn
ON
. Meter should read 105 to 125
VAC. Turn off and unplug sprayer.
5. Replace circuit breaker. See page 25.
MOTOR WON’T OPERATE
Diagnosing circuit board
indicator lamps.
The normal
condition is red lamp on, clear
lamp
on when board is telling
pump to run.
Follow
Pressure Relief Pro-
cedure W arning
. Remove
gun from hose. Remove pres-
sure control cover. Check for
faulty condition of circuit
board lamps.
Condition A
Both lamps on; pump won’t
operate and motor is not
running
