Troubleshooting Chart - Mec 4069RT Service And Parts Manual

T
ROUBLESHOOTING
The following chart is a guide to help the technician find the area of a problem. In order to
benefit from the information, you are advised to fully assess the symptoms by operating all
machine functions. There may be some functions that operate while others may not.
Record this information and proceed down the left-hand column until you find the failure
scenario that best fits the problem. Refer to the information provided to the right for possi-
ble causes and remedies. This unit contains a Microprocessor based control system
which contains various safety features designed to protect itself and the operator in the
event of a failure.
The EZ-Cal scan tool will provide the technician with detailed information related to the
failure. It is strongly recommended that the technician use the EZ-Cal to read any
displayed messages before proceeding to use this Troubleshooting chart.
Information on the use of the EZ-cal tool plus helpful Flow Charts and graphs can be
found earlier in this troubleshooting section. Please read and familiarize yourself with all of
the information provided in the troubleshooting section before attempting to diagnose or
repair the machine.
Table 4-1: Troubleshooting Chart
PROBLEM
General Power Issue
No operation from Main Battery Switch turned OFF
Upper or Lower control
Emergency Stop Switch pushed or Ignition
station
Switch turned OFF
Battery discharged or faulty cables
Circuit Breaker Tripped
Damaged Upper Control Box harness
Blown supply fuse
Other fault in system monitored
by GP400
Functions from Lower Interlock Switch (Joystick)
Controls but not from
Upper Controls
Lift/Lower
Platform will not raise Excessive weight on platform
Lift Relief Valve out of adjustment
Lift Valve not energized
Lowering valve stuck open
(located at base of lift cylinder
Level sensor out of level
(platform elevated above 10')
Main system pressure inadequate
Battery discharged - no charge output
System interruption
March 2014
Page 4-22
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HART
POSSIBLE CAUSE
"4069RT" Service and Parts Manual
T - - T
R O U B L E S H O O T I N G
REMEDY/SOLUTION
Located left of Lower Control Box
Upper or lower E-Stop will cut all power, as will the Ignition
Switch in the Upper Control Box
Will receive 4-4 or 7-7 flash on GP400.
Clean, service and charge battery - repair cables
Located in Lower Control Box Panel
Look for short circuit and/or damage in wiring or high
amperage draw at valve coils or engine actuators.
Inspect the harnesses and harness plugs for damage or
broken wires - May receive 6-6 flash code on GP-400 (CAN
bus) or no power at all
Locate source of short circuit. Inspect/replace fuse located
just below Main Battery Switch
Check HELP message on EZ-cal or check Flash Code for
error
Check power to red wire (power to switch)
and power to purple wire (power out of switch)
at the joystick plug
Reduce weight to within platform capacity
Adjust Relief Valve to rated platform capacity
Check wiring to lift valve
Check for EZ-cal message or flash code
Check and remove contamination from valve
Reposition machine to firm level surface
Check level sensor function using EZ-cal
Check pump output pressure
Check battery voltage, alternator output (14.5 volts)
Clean, service and charge battery
Check HELP messages using EZ-cal
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R O U B L E S H O O T I N G H A R T