Graco ULTRA 500 Instructions-Parts List Manual page 25

1. Remove the pressure control cover and screws.
2. Turn the pressure control knob ell the way counter-
clockwise to the minimum setting to release spring
tension on the circuit board
(23).
Also check to be
sure only three or four threads of the pressure con-
justment nut
(SI.
Beck down the nut, if necessary.
trol knob shaft are exposed below the pressure ad-
See Fig 18.
. .
I c A u T l o N
1
the circuit board while removing or installing
it.
Step 2 is essential to reduce the risk of damaging
3. Disconnect ALL wires from the board, including the
two
heavy black wires. Refer to.Fig 19. Pay close
ettention to where connections are made.
4. To remove the board from the box, pull out the
black plastic-tipped pin (330). Push the bonom of
the circuit board toward the well o f the box and
carefully slide the board out.
5.
Install the board in the box et the same angle as it
was removed. Reconnect the wires es indicated in
Fig 19. Ease the pin (330) into the retainer.
CAUTION
To reduce the risk of malfunction, be sure the flat
blade of the insulated male connector is centered
exactly in the wrap-around blade
of
the female
connector when connections are made. Route all
wires carefully to avoid interference with the cir-
cuit board, bourdon tube and pressure control
cover.
6. Perform the Stall Pressure Calibration on page
27.
19