Epson TM-U950 Technical Manual page 222

CONFIDENTIAL
Perform the following according to the recognition result:
When "?" is printed sporadically
MICR mechanism may be dirty. Clean(*1) the magnetic head and head holding roller.
Go on to the next test if "?" are still printed after the cleaning.
When "?" is printed continuously
MICR mechanism may be dirty or be damaged. Clean(*1) the magnetic head and head
holding roller. Go on to the next test if "?" are still printed after the cleaning.
(*1) To clean the head holding roller, insert the roller cleaning sheet by EPSON into the
If you don't proceed to the next test, press SLIP FEED button to skip the test, or turn the
printer power off to quit the test.
The tests numbered 3 and 4 are to check the MICR mechanism functions. For the tests, use the
specified sheets. See page 5-86.
3. Noise test
Noise level of the MICR mechanism is checked. Some sheets may have magnetic ingredients,
so please use the specified sheet.
1. Set the card-M by EPSON to the printer.
2. The printer starts noise check, and prints the results as follows:
5-84 Disassembly, Assembly, and Adjustments
If you want to cancel
paper waiting,
press SLIP FEED button.
printer. To clean the magnetic head, insert the magnetic head cleaning sheet into the
printer. For the cleaning sheets, refer to the Check sheet specification later in this
section.
(4) Checking result
MAX=*.** [V]:
MIN=*.** [V]:
P-P=*.** [V]:
mean=*.*** [V]:
σ=*.*** [V]:
(5) Wave form check. (1st)
Please set check with
magnetic ink calibration.
If you want to cancel
calibration check waiting,
Noise wave maximum value.
Noise wave minimum value.
Difference between the maximum and minumum value.
Standard: under 0.40V
Noise wave average. Standard: 2.5 +/- 0.1 V
Noise wave standard declination. Standard: under 0.045 V
Rev. A