JLG 26MRT ANSI Service Manual - Manual (Page 46)

SECTION 3 - TROUBLESHOOTING
3-2 – JLG Sizzor – 3120791
.
Table 3-1. Elevation System Troubleshooting
TROUBLE PROBABLE CAUSE REMEDY
Platform Elevation System
No Response to LIft Control
Enable switch not activated. Activate enable switch.
Lift control switch not activated within three sec-
onds after enable switch is activated. Activate enable switch, then activate lift control
switch within three seconds.
Enable circuit not functioning properly. Replace enable circuit card.
Lift control switch inoperative. Repair or replace control switch.
Hydraulic system oil low. Replenish oil as necessary.
Restricted or broken supply line on valve
bank or pump. Clean, repair or replace line.
Control valve not functioning properly. Repair or replace valve.
Lift cylinder not functioning properly. Repair or replace cylinder.
Hydraulic pump not functioning properly. Repair or replace pump.
Platform will not raise.
Enable switch not activated. Activate enable switch.
Lift control switch not activated within
three seconds after enable switch is acti-
vated. Activate enable switch, then activate lift
control switch within three seconds.
Enable circuit not functioning properly. Replace enable circuit card.
Load capacity exceeded. (Personnel
and/or equipment on platform). Reduce load. (Refer to capacity placard).
Hydraulic system oil low. Replenish oil as necessary.
Restricted or broken hydraulic line or fit-
ting. Clean, repair, or replace line or fitting.
Control valve not functioning properly. Repair or replace valve.
Lift cylinder not functioning properly. Repair or replace lift cylinder.
Engine does not respond when lift control
switch is moved to up position. Refer to Electrical System Troubleshoot-
ing - No response to control switch.
No electrical signal being sent to lift up control valve
cartridge. Refer to Electrical System Troubleshooting - No
response to control switch.
Platform will not lower
Enable switch not activated. Activate enable switch.
Lift switch not activated within three sec.
after enable switch is activated. Depress lift switch, then activate control-
ler within three seconds.
Enable circuit not functioning properly. Replace enable circuit card.
No electrical signal sent to lift down con-
trol valve cartridge. Refer to Electrical System Troubleshoot-
ing - No response to control switch.
Lift down control valve cartridge not functioning
properly. Repair or replace lift down control valve
cartridge.
Lift cylinder not functioning properly. Repair or replace lift cylinder.
Engine does not respond when lift switch
is moved to down position. Refer to Electrical System Troubleshoot
ing - No response to control switch.
No electrical signal being sent to lift down
control valve. Refer to Electrical System Troubleshoot
ing - No response to control switch.