3M SST, Manual

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SST Transport and Burster Mechanism Manual 75-0302-1450-8, Version 1 Ch. 6 Performing Field Repairs • 53
Adjusting Belt Tension
Improper belt tension can cause the SST/HP-4 Transport to print characters of uneven height. It
may also cause the unit to encode or read the magnetic tickets poorly. Test the belt by gently push-
ing, or deflecting, the lower belt up or down. The belt should move as least 1/16 in (1.6 mm). You
should also be able to manually move the upper belt. If you cannot do this, adjust the lower and/or
upper belts by completing the following steps:
1. Back out any tickets, if applicable, from the SST/HP-4 Transport by using the green but-
ton on the SST CPU Board.
Warning! Disconnect power from the SST CPU Board. If you do not disconnect power, you
will damage the unit and severe personal injury may occur.
2. Open the cabinet of the device in which the SST/HP-4 Transport resides and remove the
unit. Close the cabinet.
Note: Do not carry the SST/HP-4 Transport by the Print Head. Carrying it by the Print Head may
bend the bracket and cause printing problems. Always carry the SST/HP-4 Transport from
the bottom.
3. Adjust the Upper Drive Belt by completing the following steps:
❑
Using a Phillips screwdriver, loosen the screw on the Upper Belt Tensioner. If
necessary, use pliers to hold the nut on the back side of the panel. Figure 6.3
illustrates the location of the Upper Belt Tensioner on the SST/HP-1 Transport.
Figure 6.4 illustrates the location of the Upper Belt Tensioner on the SST/HP-4
Transport.