Graco A Series Instructions-Parts List Manual page 14

YPE OF PROBLEM
IOTOR W O N 7 OPERATE
iagnosing circuit board in-
cator lamps. The normal
mdition is red lamp on,
ear lamp on when board is
luing pump to run.
dlow Pressure Relief Pro-
dura. Remove gun from
DW.
Remove pressure con-
01 cover and check for faulb
mdition of circuit board
mps.
ondition A both lamps on;
ump won't operate and
lotor is not running
:ondition
B
loth lamps off
WHAT TO CHECK
I f check Is
OK,
t o to next check
.
Check leads from bridge (308) to motor to be
,sure they are securely fastened and properly
mated.
!.
Check G1 and
62
connections between cir-
cuit board (23) and bridge
(3081
for damage
or loose terminals.
I. Check for loose motor brush lead connec-
tions and terminals. See page
22.
1. Check brush length which should be 1/2"
'
minimum. See page 22.
the sarna rate on both sides of the motor.
NOTE also that the brushes do not wear a t
i. Check for broken or misaligned motor brush
springs. Rolled portion of spring must rest
squarely on top of brush. See page
22.
i.
Check motor brushes for binding in brush
holders. See page 22.
1.
Check motor armature commutator for burn
spots, gouges and extreme roughness.
plates to check. See page
2 2 .
Remove motor cover and brush inspection
mature tester (growler) or perform spin test.
See
page
19.
good bridge or performing bridge tat. See
page 20.
armature is determined to be good. A bad
CAUTION: Do not perform this check until
armature will immediately burn out a good
bridge.
1. Check circuit breaker
(3091
bunon to be sure
it has not popped up.
3. Check motor armature for shorts using ar-
3. Check bridge (308) by substituting with a
2. Check sprayer power supply cord (3111.
connect volt meter to these leads. Plug in
Disconnect TP6 female end TP1 female and
sprayer. Meter should read 105 to 125 VAC.
Unplug sprayer. Reconnect TP1.
3.
Check ONlOFF switch
(3031.
Disconnect TPi
and connect volt meter to TP6 female and
TP2 male. Plug in sprayer and turn on. Metel
should read 105 to 125 VAC. Turn off and
unolua sDraver. Reconnect TP2.
1. Check jumper wire (306). Disconnect TP3
and
conneci
volt meter to TP6 female and
__
~~
~. .
~~ ~~
TP3 female. Plug in sprayer and turn on.
Meter should read 105 to 126 VAC. Turn off
and unplug sprayer. Reconnect TP3.
5. Check circuit breaker
(309).
Connect volt
meter to TP6 female and TP4. Plug in
sprayer and turn on. Meter should read 105
to 125 VAC. Turn off and unplug sprayer.
WHAT TO DO
When check Is not
OK
refer to this columl
Replace any l o o s e terminals and wimp to
straight and firmly connected to mating part
leads.
Be
sure male terminal blades are
Clean circuit board male terminals. Replace
loose or damaged terminals. Securely recon-
nect leads.
Tighten terminal
screws.
Replace brushes if
leads are damaged.
See
page
22.
Replace brushes. See page
22.
Replace spring if broken. Realign spring witt
brush. See page
22.
Clean brush holders. Remove carbon with
small cleaning brush. Align brush lead with
slot in brush holder to assure free vertical
brush movement.
Remove motor and have motor shop resur-
face commutator if possible. See page
30.
Replace motor. See page
3 0 .
Replace bridge.
See
page 24..
Depress circuit breaker button to reset. If cil
trical Short", page 16.
cult breaker continues to open, see "Elec-
Replace power supply cord. See page
23.
Replace ONlOFF switch. See page
21.
Replace jumper wire. See page 25.
Replace circuit breaker. See page 24.
(Continued)
(Continued)
Troubleshooting continued on nextpage