Epson TM-U950 Technical Manual page 223

CONFIDENTIAL
4. Output voltage test
Press SLIP FEED button to end the test.
Rev. A
press SLIP FEED button.
If P-P, mean, or σ value is over the standard value, MICR mechanism may be dirty.
Clean(*1) the magnetic head and head holding roller.
(*1) To clean the head holding roller, insert the roller cleaning sheet by EPSON to the
printer. To clean the magnetic head, insert the magnetic head cleaning sheet to the
printer. For the cleaning sheets, refer to the Check sheet specification later in this
section.
The output voltage level at the magnetic character reading is checked. Use E13 side when
performing the test.
1. Set the calibration check sheet by EPSON to the printer.
2. Printer starts the test, and prints the result as follows:
(6) Checking result
Peak level
upper
MIN=*.** [V] Output voltage minimum value at upper side. Standard: above 3.0 V
P-P=*.** [V] Output voltage difference between maximum and minimum value. Standard:
lower
MAX=*.** [V] Output voltage maximum value at lower side. Standard: below 2.0 V
P-P=*.** [V] Output voltage difference between maximum and minimum value. Standard:
(7) Wave form check. (2nd)
Please set check with
magnetic ink calibration.
If you want to cancel
calibration check waiting,
press SLIP FEED button.
If the values are out of the standard, the magnetic head may be dirty or the MICR
mechanism may be damaged. Insert a magnetic head cleaning sheet to the printer to clean
the head. If the output voltage value is out of the standard value but the noise level is within
the standard value, disassemble the printer to check the magnetic head and paper holding
roller.
Please note that all of the MAX, MIN and P-P values are printed for upper and lower side if
the printer's ROM version is 1.00 ESC/POS. But only the items in the printing result sample
shown above is requied. Also the pitch value is printed, but ignore the value as it is not
needed.
TM-U950/U950P Technical Manual
below 1.2 V
below 1.2 V
Disassembly, Assembly, and Adjustments 5-85