Checking And Adjusting The Micr Check Reader (Lcsio-Rs-485 Micr Amplifier Board) - NCR 7156 Service Manual

Chapter 3: Diagnostics
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10. Set the DIP switches back to the settings for normal operation (on-line mode).
11. Reattach and close the front cover if it was removed.
12. Press the On Line button (or plunger) on those models to put the printer on-line.
13. Press the reset button on those models (under the DIP switches) to put the printer on-
Checking and Adjusting the MICR Check Reader (LCSIO—RS-485 MICR Amplifier Board)
The adjustment procedure described in this section cancels or sharply reduces extraneous
signals picked up by the Magnetic Ink Character Recognition (MICR) check reader.
Use these procedures only on LCSIO (RS-485) models with the MICR amplifier board.
These models are earlier LCSIO (RS-485) models as compared to newer models with the
common PC board that no longer use the MICR amplifier board. If the printer does not
have the MICR amplifier board, see the previous section, "Checking and Adjusting the
MICR Check Reader (Common Board and RS-232C Models)."
Note: The MICR check reader feature has been factory adjusted for a normal operating
environment with a host computer. However, additional devices, such as CRT monitors or
large metal surfaces near the printer, can affect the printer's magnetic field, causing
intermittent reading errors when the MICR check reader is in operation.
This condition can be easily diagnosed by checking the MICR check reader adjustment and
readjusting it if the factory setting has been altered. Follow the procedures in this section to
check and adjust the MICR check reader.
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Set both potentiometers (on the PC board) to mid range using a screwdriver.
Adjust the lower potentiometer (R9) on the PC board either direction.
The green LED should be on before you adjust the potentiometer.
Press the paper feed button on the PC board to take a noise sample.
Repeat steps 4 and 5 until the lowest number of characters is printed. You may need to
adjust the potentiometer both directions to get the best setting.
If "OK" is printed on the receipt, go to number 8 or 9 depending on which printer
model you have.
Adjust the upper potentiometer (R8) on the PC board either direction.
The green LED should be on before you adjust the potentiometer.
Press the paper feed button on the PC board to take a noise sample.
Repeat steps 6 and 7 until the lowest number of characters is printed. Adjust the
potentiometer both directions to get the best setting. When "OK" is printed, the noise
is low enough for the MICR to operate successfully.
On models with the On Line button (or plunger) on top of the printer, press the On
Line button (or plunger) to put the printer off-line.
On models without the On Line button (or plunger), press the reset button (under the
DIP switches).
See "Appendix B: Communication Information" for the settings.
The green LED flashes when the printer cycles. The settings are entered into EEROM.
line.
The green LED flashes when the printer cycles. The settings are entered into EEROM.
September 1998
7156 Service Guide