Technical data

Table 4–7: Service Aid 125 Front Panel Switches
Switch Function
1 Selects the next message prompt.
2 Selects the previous message prompt.
3 Displays the revision level or interface type, depending on which message type is selected.
4 Exits the service aid.
5 No function.
4.5.2.3 Service Aid 131 (Sensors)
Service Aid 131 checks the status and operation of the file protect/reel seat, BOT, EOT, and
tape-in-path sensors.
The file protect/reel seat sensor is tested by placing a tape reel with a write-enable ring on
the supply hub and starting the test. The test begins by slowly rotating the supply hub. As
the supply hub rotates, the Unload indicator flashes twice when the reel seat tab passes the
sensor. The Unload indicator flashes once when the file protect tab passes the sensor.
The tape-in-path, BOT, and EOT sensors are tested by passing a length of tape with both
BOT and EOT reflective markers through the tape path. While the service aid is running, the
letters "B," "E," and "T" appear in the display. When the tape reaches the tape-in-path sensor,
the "T" disappears from the display. When the tape reaches the BOT and EOT sensors, the
"B" and "E" disappear from the display. When the reflective markers move past the BOT and
EOT sensors, the "B" and "E" reappear.
Service Aid 131 can also be used to check the sensitivity of the BOT and EOT sensors to
shiny tape, which can produce false BOT and EOT signals. Place a dull, non-shiny covering
over the reflective material opposite the BOT and EOT sensors. Place a piece of shiny tape
in the tape path and hold it taut. Use a pencil or similar object to disturb the tape near the
sensors. If a "B," "E," or "S" does not appear in the display, the sensor passes. If only an "S"
appears, the sensors are acceptable but marginal. If a "B" or "E" appears, shiny tape should
not be used, or else the sensors should be replaced.
4.5.2.4 Service Aid 132 (Solenoids)
Service Aid 132 cycles the supply hub and front door lock solenoids. When the solenoids are
energized with the front door closed, LOCKED appears in the display. When the solenoids
are energized with the front door opened, UNLOCKED appears at the display.
Pressing switch 1 stops the cycling action and the message SW CLOSD appears in the display.
The switch must be pressed a second time to resume the cycling action. If the front door is
opened when the switch is pressed, the message SW OPEN appears.
4–12 Troubleshooting