Electrical Tests
Test Power Supply Resistance
(See Fig. 17)
Remove the power supply (40) from the gun body (29)
as instructed on
page 36.
Measure the resistance from the power supply’s
ground contact point (R) to the contact inside of the
power supply seal (40d)
[the conductive rubber contact
may be slightly recessed into the seal].
The resistance should be 297 to 363 megohms. If the
resistance is outside the specified range, the power
supply is defective and must be replaced. If the resis-
tance of the power supply is correct, proceed to the
next test.
NOTE: Be sure the seal (40d) is in place on the end of
the power supply before installing the power supply
back into the gun.
Test Resistor Stud Resistance (See Fig.
18)
Remove the resistor stud (15) as instructed on page
30. Check the resistance between the black resistor
stud ring contact (S) and the needle contact ring (T).
You may have to press down on the contact ring (S) in
several places to get a good reading.
The resistance should be 21 to 29 megohms. If the
resistance is correct, make sure the metal contact in
the gun barrel and the needle contact ring (T) are
clean. If the resistance is outside the specified range,
the resistor is defective and the resistor stud (15) must
be replaced. See page 30 to replace the resistor stud.
FIRE, EXPLOSION, AND ELECTRIC
SHOCK HAZARD
The resistor stud contact ring (S) is a
conductive contact ring, not a sealing
o-ring. See Fig. 18. To reduce the risk of
sparking, which could cause a fire,
explosion, or electric shock,
do not
remove the contact ring (S) from the re-
sistor stud or operate the gun without
the contact ring in place. If the resistor
stud (15) is being replaced, only use a
genuine Graco part.
WARNING
If you still have problems, refer to
Electrical Trouble-
shooting for other possible causes of poor perform-
ance, or contact the nearest authorized service
agency.
Fig. 17
40
R
L
40d
0441
Fig. 18
S
T
0442
15
