CP60 and CP60 Plus Service Manual  4-3 
 
 
Troubleshooting Sensors 
This procedure is used to determine if a sensor has failed or if the main control 
board is not seeing the sensor properly. The first step in troubleshooting a sensor 
is to determine if the sensor is toggling from an active state to an inactive state as 
a physical condition changes.  
1.  Verify that the sensor is fully plugged in to the control board. In some cases, 
an unplugged sensor will be displayed as “active” in the Diagnostics 
window. 
2.  Using Diagnostics, observe the sensor status indicator as the sensor is 
blocked and unblocked.  
•  To test the ribbon index sensor, remove the ribbon cartridge, and open 
and close the swingarm. (Also verify that the reflector is in position on 
the printhead). 
•  To test the magnetic stripe registration sensor, slide a card between the 
sensor and the reflector on the rocker arm.  
•  Because the ribbon motion sensor has two channels, the only way to 
verify that both channels are functioning is with a volt meter. Use the test 
points in the figure below to test the sensor. 
 
3.  Unplug the printer and swap the sensor with another sensor: 
 You cannot swap the ribbon motion sensor with any other sensor. It is not 
compatible with any other sensor. 
•  Because this is a test of the sensor, the original sensor does not need to be 
removed. Simply unplug the original sensor from the control board and 
plug in a replacement sensor. 
•  If a spare sensor is not available, you can use an adjacent sensor from 
within the printer. (Except for the ribbon motion sensor, all sensors are 
electrically compatible.) 
•  The sensor does not need to be the same type. For example, a 
transmissive sensor can be used in place of a reflective sensor. (The 
transmissive sensor is easier to block and unblock.) 
4.  If the replacement sensor functions, then the original sensor is defective. 
Verify this by reconnecting the original sensor. 
5.  If the replacement sensor is non-functional and other sensors in the printer 
are observed to be functional, then the main control board is defective. (If 
none of the sensors are functional, you may have a communication problem 
between the printer and Diagnostics.)