T-SM47j P17/54
T20-a
OPERATION TABLE
5.0 MAINTENANCE
5.1 Power supply assembly
This assembly (Part number 111765) which is located in
the table base, has no user serviceable parts and must be
changed as a complete unit (also see section 3.1).
5.2 Table fault finding
5.2.1 The ‘Instructions for use’ contains a basic fault finding
table that can be used to solve any minor problems. This
covers the main user errors (i.e. there is no fault) that can
occur when the user has not read and understood the
‘Instructions for use’. It also contains the first line of fault
finding (i.e. check external fuses, try another handset, try
another mains lead). The following section (5.2.2) provides
a test sequence to help determine the fault (for the majority
of faults that may occur) that could stop the table responding
to an input via a control device. Mechanical faults are
normally self evident in that a part is worn, damaged or
broken. In this case refer to the appropriate section of this
manual for part replacement information. Appendix 3
provides the schematic diagrammes that can also be used
in fault finding.
5.2.2 Follow the sequence below to identify most major
faults that result in a lack of response to a control command:
1 When the table is initially switched ‘on’ is the table
‘on’ LED (item 23 of Fig. 1.0) bright, dull or ‘off’ for
the first few seconds.
If dull turn the table ‘off’ wait at least 10 seconds
and then turn back on. If the LED is still dull or
‘off’ this indicates an electronics fault see 5.2.3.
If bright move to 2 below.
If it is flashing this also indicates an electronics
fault see 5.2.3.
2 Try the ‘standby control panel’ (any motion except
Trendelenburg), if this fails try the ‘standby control
panel’ with the backup battery switch depressed.
If the table works from the ‘standby control panel’
this indicates a fault with the control device or
its connection to the table.
If the table works from the ‘standby control panel’
only when the backup battery switch is pressed
this indicates a fault with the main batteries
(replace the whole Power supply unit).
Now try Trendelenburg from the ‘standby control
panel’, if this and only this motion works it indicates
a problem with the main control PCA.
3 If one of the motor groups ‘only’ has failed then this
indicates a problem with its associated PCA as follows:
Break and traverse - Three actuator PCA
Tilt, Trend and Height - 4 Actuator PCA
This distinction may help in reducing the amount of
diagnostics and cover removal.
4 Remove covers and check battery fuses (see
section 5.3.1 and 6.6.26). Also look to see if the
PCA indicator lights are flashing ‘on’ for 1 second
and ‘off’ for 1 second. If they are ‘off’ or flashing
faster, this indicates an electronics fault see 5.2.3.
5 If the fault is only apparent for one motion this could
indicate a failed motor or failed sensor for that motion,
or, an electronics fault. If the motion starts and then
stops immediately this could indicate a failed sensor
or an over current situation. Test motor (as detailed
in section 6.6), if the motor works and no small
movement is observed following a demand for that
motion, it indicates an electronics fault, see 5.2.3.
5.2.3 Electronic faults can only be determined with the
table connected to a PC with the ‘T20 Application Software’
installed. Consult the Application Software Manual (as
detailed in section 1.1) which provides guidance on fault
diagnosis. Also note that when correcting electronic faults
(and following some parts replacement) the table will require
reprogramming, reconfiguring or recalibration. These aspects
are also fully covered in the Application Software Manual.
5.2.4 Break motion control
5.2.4.1 The two break arms are independently controlled
and are synchronised to operate within a programmed limit
of each other. This control system can result in small
variances that appear as a slight misalignment, this is
acceptable and a part of the normal table control software
routine. In the unlikely event that this deviation goes outside
of the programmed limit the table break motion (only) will
stop working. This can sometimes be corrected as below.
5.2.4.2 Whilst observing the two break arms press (for
approximately 0.5 seconds only) a break control button on
the handset (B7 or B8 of Fig. 6.9) once or twice. If this
makes the deviation worse press the other break control
button as above once or twice. If the break motion still
does not work correctly after this there could be a fault in
one of the following:
Break motor
Break potentiometer
Wiring to any of the above
Significant uneven table loading*
*This problem will only be evident during use and if
investigated at service it will be difficult to reproduce.
5.2.5 Trunk section connector blocks
5.2.5.1 If all the top table functions stop working (e.g. break
and traverse) the connector blocks (item 5, Fig. 6.7 and item
14, Fig 6.3) could be failing to connect correctly due to
contamination etc. Check that a good contact is being made
between the column and trunks connector blocks.
5.3 Fuse location
5.3.1 All fuse locations are identified in section 2.5.4 and
Fig. 1.0. DO NOT REMOVE OR CHANGE INLINE BATTERY
FUSES UNLESS YOU HAVE READ SECTION 6.6.26.
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