Xerox 6100BD - Phaser Color Laser Printer Fundamentals page 120

Problem solving
7-8
A statistically significant test to detect a 0.5 per cent rejection
rate can be achieved with 2,000 to 3,000 documents. (The
test case should not be less than 200 documents.) If the test
set is too small, it may be biased by the fact that reader sorter
performance is poorer when the machine is starting up than
when it has been operating steadily for some time.
• Are there characters that appear more often as the reason for
rejection?
Although a reject rate based on character failure is not
generally significant, a specific character may be causing the
problem. Check to see if a certain character is driving the
reject rate, and if failure occurs when the character is in a
particular position in the document.
• Are the rejects clustered by field?
If multiple rejects occur in a particular field, a mechanical
problem may exist in the printer or the reader sorter.
• Is there a pattern to where the rejects occur?
Rejects can appear in the document consecutively, in groups,
or randomly. Look for a pattern; for example, the same
character, the same field, or appearance after every certain
number of sheets.
• How do the rejects compare with accepted documents?
Check to see if the rejects have been improperly cut, or if any
other difference is obvious.
• Are all documents accounted for?
At the end of a run, the number of accepts plus the number of
rejects should equal the total number of documents
submitted.
• What is the sorter type and location?
If there are problems, it may be useful to know what type of
sorter was used. If possible, obtain the following information
for reference and machine identification purposes: sorter
type, model number, user ID, and serial number.
Generic MICR Fundamentals Guide