Thermistor Open Error; Power Supply Fan Does Not Run; Front Panel Cycling Between Ready And Warming Up - Tektronix Phaser 550 Service Manual

6
Troubleshooting
6-18 Phaser 550 Color Printer

Thermistor open error

1.
Check the connector CN12 on the engine control board.
2. Ensure a 110 volt fuser has not been installed in a 220 volt printer; it
will damage the power supply thermistor and require the power
supply be replaced.
3.
Replace the fuser.
4. Replace the engine control board.

Power supply fan does not run

1. Is 24 V output at CN853? If not, replace the power supply.
2.
Replace the power supply fan.

Front Panel Cycling between READY and WARMING UP

3.
Make sure that the fuser, imaging unit, and toner cartridges are well
seated.
4. Invoke a test print from the Front Panel to try to get an error message
to be displayed that may be present but, is masked by the front panel
cycling between READY and WARMING UP.
5.
Check the dip switches on the engine drive board; SW301 switch 4
should be up, all the rest should be down.
6. Make sure all connectors to the circuit boards are well seated and
make sure that the screws holding the boards's in place are tight.