NCR 7156, Руководство по эксплуатации и устранению неисправностей

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26 Chapter 3: In-Place MICR Adjustment
Printout Value Meaning
“OK” Optimum setting
“ABCDE” or
“ABCDEF” Maximum acceptable interference
“ABCDEFG” and
greater Interference too high; repeat adjustment
procedure
A variation of plus or minus one character from line to line is
normal. Greater variation indicates either a poor connection to the
buck coil or a faulty read head. For more information, see
“Incorrect Printer Installation, Electrical Grounding or Bonding, or
MICR Adjustment” on page 8. (First check that the CRT is either
turned off or moved at least 3 inches from the printer.)
4. Set both pots (on the PC board) to the mid-range.
Adjusting the pots is interactive—changing the setting of one pot
affects the other. The pots are not coarse/fine adjustments.
5. Adjust the first pot about 10 degrees or less in either direction.
Make very small adjustments as the optimum setting is
approached.
6. Repeat steps 2-3.
7. Repeat steps 5-6 until the best (lowest) indication is printed. If an
“OK” prints three times in succession, go to step 12.
8. Adjust the second pot about 10 degrees or less in either direction.
Make very small adjustments as the optimum setting is
approached.
9. Repeat steps 2-3.
10. Repeat steps 8-9 until the best (lowest) indication is printed. If an
“OK” prints three times in succession, go to step 12.
11. Repeat steps 5-10 until an “OK” prints three times in succession.
12. When the adjustment is complete, remove the blank sheet of paper,
replace the cover, and reset the DIP switches for normal use.