JLG 120HX ANSI Service Manual - Manual (Page 70)

SECTION 2 - PROCEDURES
2-50 – JLG Lift – 3120686
7. Check the mA reading in the opposite direction.
8. Operate the controller until 1/2 of the slide lock is out
of the housing lock notch. Hold the control handle in
that position. Check the mA reading.
9. Verify step 7 and step 8 mA readings are within 0.50
mA of each other. If the readings are within toler-
ance, proceed to step 11.
10. If the readings in step 9 were not within tolerance,
Loosen the setscrew located in the gear on the
potentiometer shaft of the controller. Using a screw-
driver, adjust the potentiometer very slightly in either
direction. Tighten the setscrew on the gear and
recheck for the proper mA readings. Repeat this
step until the proper adjustment is obtained.
11. Place the creep toggle switch in the off position.
12. Position the Controller as outlined in step 6. Using
correct size common blade screwdriver, adjust LO
trimpot until ammeter indicates the proper value as
shown in Table 2-6, Platform Controller Settings (S/N
38697 to Present). Clockwise rotation of trimpot
adjust screw increases ammeter; counterclockwise
rotation decreases ammeter reading.
13. Operate controller in the same direction as in step 6
to the full extent of its travel and hold handle in that
position.
14. Adjust HI trimpot until ammeter indicates the value
shown in Table 2-6, Platform Controller Settings (S/N
38697 to Present).
15. Repeat step 13.
16. Place the creep toggle switch in the creep on posi-
tion. Adjust the mid trimpot to the value shown in
Table 2-6, Platform Controller Settings (S/N 38697 to
Present) for mid.
17. Move controller handle back to the position given in
step 6 and check ammeter reading. This reading will
have changed due to HI trimpot adjustment, and
must be readjusted back to the value shown in Table
2-6, Platform Controller Settings (S/N 38697 to
Present).
18. Move handle to the position given in step 13 and
check ammeter reading. This reading too will have
changed due to LO trimpot readjustment, and must
be adjusted back to the value shown in Table 2-6,
Platform Controller Settings (S/N 38697 to Present).
19. Move controller handle back to the position given in
step 6 and check ammeter reading. This reading will
have changed due to MID trimpot adjustment, and
must be readjusted back to the value shown in Table
2-6, Platform Controller Settings (S/N 38697 to
Present).
20. Repeat steps 17 and 18 until LO and HI readings as
shown in Table 2-6, Platform Controller Settings (S/N
38697 to Present) can be achieved without further
trimpot adjustments.
21. Adjust the Ramp trimpot clockwise according to
Table 2-6, Platform Controller Settings (S/N 38697 to
Present).
22. Release footswitch.
23. Using all applicable safety precautions, start
machine and allow hydraulic oil to reach a tempera-
ture of 100° F - 140° F (38° - 60° C).
24. Depress footswitch and operate controller until 1/2
of slide lock is out of the housing lock notch. Hold
control handle in that position.
25. Adjust LO trimpot until applicable function just starts
to work. Immediately stop adjustment.
26. Release footswitch and stop machine.
27. Seal each trimpot with a drop of enamel paint to pre-
vent maladjustment due to vibration.