JLG 26MRT Service & Maintenance page 46

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