Intermec EasyCoder 501 XP Service Manual page 39

Chapter 7 Transfer Ribbon Mechanism
7.4 Ribbon End
Sensor, cont.
38
Adjustments
The intensity of the light emitted from the sensor is controlled by
a strap on P56 on the CPU board:
Strap fi tted = higher intensity
Strap removed = lower intensity
The sensitivity of the receiver is controlled by the potentiometer
WR52 on the CPU board.
Before adjusting the sensor, check that the sensor and the mirror
are clean and free from obstructions.
A simple program can be used to check the ribbon end sensor, for
example:
10 'RIBBON END SENSOR TEST
20 'INTERRUPT PROGRAM BY TYPING "X"
30 BREAK 1,88:BREAK 1 ON
40 ON BREAK 1 GOSUB 1000
50 IF (PRSTAT AND 8) THEN SOUND 100,50 ELSE BEEP
60 GOTO 50
70 END
1000 BREAK 1 OFF
1010 GOTO 70
RUN
Remove the transfer ribbon from the sensor's beam of light (for
example by pulling out a loop) and run the program. The printer
should emit a low sound.
Put back the ribbon into the beam and the printer should start to
beep with a high-pitch tone.
If the printer does not behave as described, remove the left-hand
cover and, with the power still on, turn the potentiometer marked
"RI-END" (WR52) at the upper edge of the CPU board back and
forth. If that does not help, fi t or remove the jumper on P56.
If the sensor refuses to work, consider the possibility that the mirror
plate may be bent before discarding the sensor.
Intermec EasyCoder 501 XP – Service Manual Ed. 4