Intermec EasyCoder 501 – Service Manual Ed. 7
42
Chapter 7 Transfer Ribbon Mechanism
7.4 Ribbon End
Sensor, cont.
The intensity of the light emitted from the sensor is controlled by
a strap on P-604 on the CPU board:
Strap fi tted = higher intensity
Strap removed = lower intensity
The sensitivity of the receiver is controlled by the potentiometer
WR-601 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
“R-END” (WR-601) at the upper edge of the CPU board back and
forth. If that does not help, fi t or remove the jumper on P-604.
If the sensor refuses to work, consider the possibility that the
mirror plate may be bent before discarding the sensor.