Technical Service Manual M9 Transfer Stretcher (M999-29, Version 11, June 2021)
37
8. CONTROL SYSTEM TROUBLESHOOTING
High low actuators have
lost position and software
has halted operation.
Press any handset button and
observe any movement - listen for
single beep in control box.
Reset the control box:
1) Using the hand set press and hold
both the DECK UP and DECK DOWN
buttons simultaneously. Stretcher will
beep 10 times. When beeping stops
control box is reset.
FOR STRETCHERS BUILT BEFORE
AUGUST 2015.
2)Then press the deck up button until
the stretcher reaches its full height.
FOR STRETCHERS BUILT AFTER
AUGUST 2015.
3)Then initialise the control box by
holding down the two top buttons
(BACKREST UP and BACKREST
DOWN) on the handset, until the
stretcher stops moving and beeping.
Actuator, control box or
actuator cable failure.
1) Disconnect plug from mains
supply.
2) Disconnect actuator cables from
ports 2 & 4 on control box (these are
the high-low actuator ports)
3) Reset the control box and operate
the backrest and then kneebreak.
If the backrest and kneebreak oper-
ate then it is likely a problem with
the high-low actuators or high-low
actuator cables.
Replace each high-low actuator one
at a time to determine which actuator
has failed.
If the problem is still present then
replace the high-low actuator cables.
If the problem is still present then
replace the control box.
Bed will function but
not under load.
Battery charge is low and
power cord is not plugged
into mains supply.
Check that power cord is plugged
into mains supply.
Plug power cord into mains supply.
RCD (if fitted) is tripped
and the battery is flat.
Check the RCD.
Plug the power cord into the mains
supply and reset the RCD.
Control box failure or an
actuator failure causing
excessive current draw.
1) Load bed to 150kg.
2) Operate handset buttons and
determine any function or a failed
actuator.
2) Trace failed actuator cable back
to control box.
3) Swap failed actuator cable with
either a known working backrest ac-
tuator port or legraise actuator port
and operate handset to determine
whether the actuator has failed of a
channel on the control box has failed.
Replace either the failed actuator
or control box as determined by the
investigation.
CB16 SYSTEM
continued.