NCR 7156, Service Manual

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7156 Service Guide Chapter 3: Diagnostics
September 1998 31
Access the MICR Amplifier Board
Do the following steps to remove the receipt and top covers. Be sure there is paper in the
receipt bucket.
1. Turn the power to the printer off by turning the host computer off.
2. Remove the receipt cover by opening it and pulling it gently upward and slightly to
the right to detach it from the printer at its hinges, while maintaining gentle pressure
on the left back edge of the cabinet.
3. Remove the top cover.
a. With the front cover open, use a screwdriver to push and release the large snap
holding the top cover to the top of the cantilever.
b. Release the snap at the base (near slip table) on the left side of top cover.
c. Remove the ESD tab wire on the cantilever.
d. Partially close the front cover and lift off the top cover by pulling the rear wall of
the top cover slightly back to release the tabs from the base.
4. Replace the receipt cover.
a. Hold the receipt cover vertically over the hinge brackets in the printer.
b. Align the hinges.
c. Push down gently until the cover snaps into place.
d. Close the receipt cover by pushing it down until it latches into place.
Check the MICR Check Reader Adjustment
Caution: Electro Static Discharge may damage the PC board. Wear a grounded wrist strap
and use a static mat or other ESD protected work surface whenever you work with the PC
board.
1. Open the front cover and set the switches to the settings in the table.
Caution:
The DIP switches are pre-set at the factory and should generally not be changed.
If you must change them, do so carefully to avoid changing other functions.
Switch 1 Switch 2 Switch 3 Switch 4 Switch 5 Switch 6 Switch 7
On Off Off Off Off Off On