Kipp&Zonen Brewer MkIII - Manual (Page 32)

MKIII SERVICE MANUAL 27
5
If no pulses are seen at the Tracker, then look on pin 4, J17T on the Main Electronics board.
This pin is the 2
nd from the left on the top row of solder connections just behind J17T when
facing the removable plate of the Main Board.
6
If there are still no pulses, then remove the connector at the BA-C99 end and try again – this
will test for a short circuit in the cable
7
If the test fails again, then a fault is indicated in the motor driver circuitry on the Main
Electronics Board, and this board should be replaced.
8
If it is confirmed that pulses are going to the Tracker and if the Tracker Power Supply and
Safety Switch are both normal, and there is still no motor motion, then the motor Driver board
in the Tracker should be replaced.
9
Failure of the motor to move under command at this point indicates a possible motor failure, or
a failure of interconnecting cables. All interconnections should be inspected.
7.4
TRACKER MECHANICAL PROBLEMS
If the Tracker stepping motor is observed to rotate, but the Tracker does not turn, or turns
erratically, this is an indication of a mechanical problem.
The first check should be for cleanliness of the aluminum drive plate, and particles jamming
between drive gears.
A rare mechanical problem is the seizing of the main bearings, which can be checked by turning
Tracker power off and attempting to rotate the Tracker by hand. If the Tracker does not turn freely,
then KIPP & ZONEN should be consulted.
If the Tracker turns freely with no power, and the motor turns when an AZ or SR command is
issued, then a mechanical problem exists between the motor and the main drive plate.
Check the small motor gear and confirm that it is turning with the motor, and is not slipping on the
gear with which it is meshing. Also check for slippage between the stainless steel drive rod and the
large aluminum drive plate.
If the motor gear does not turn with the motor, then check the set screw which holds the gear to the
motor shaft. If the motor gear turns, then the spring tensions that provide drive friction between the
gears, the drive shaft, and the drive plate may require adjustment. (Ref Figure 7.1 and Section 5.4
of the Operator’s Manual).
A spring scale can be used at the top and bottom of the shaft and the tension adjustments set to
4kg at the top, and 9kg at the bottom tension point.
If the Tracker still does not turn, or gives inconsistent SR results, then KIPP & ZONEN should be
contacted for assistance.
7 AZIMUTH TRACKER