Service Manual vii
Service Safety Summary
General Guidelines
For qualified service personnel only: Refer also to the preceding Power Safety 
Precautions.
Avoid servicing alone:  Do not perform internal service or adjustment of this 
product unless another person capable of rendering first aid or resuscitation is present. 
Use care when servicing with power:  Dangerous voltages may exist at several 
points in this product. To avoid personal injury, do not touch exposed connections and 
components while power is on. Disconnect power before removing the power supply 
shield or replacing components.
Do not wear jewelry:  Remove jewelry prior to servicing. Rings, necklaces and 
other metallic objects could come into contact with dangerous voltages and currents.
Power source:  This product is intended to operate from a power source that will 
not apply more then 264 volts RMS for a 220 volt AC outlet or 140 volts RMS for a 
110 volt AC outlet between the supply conductors or between either supply conductor 
and ground. A protective ground connection by way of the grounding conductor in 
the power cord is essential for safe operation.
Warning Labels
Read and obey all posted warning labels. Throughout the printer, warning labels are 
displayed on potentially dangerous components. As you service the printer, check to 
make certain that all warning labels remain in place. 
Safety Interlocks
Make sure all covers and the printer’s front panel are in place and all interlock 
switches are functioning correctly after you have completed a printer service call. If 
you bypass an interlock switch during a service call, use extreme caution when 
working on or around the printer.
CLASS 1 LASER PRODUCT
The Phaser 7750 Color Laser Printer is certified to comply with Laser Product 
Performance Standards set by the U.S. Department of Health and Human Services as 
a Class 1 Laser Product. This means that this is a class of laser product that does not 
emit hazardous laser radiation; this is possible only because the laser beam is totally 
enclosed during all modes of customer operation. When servicing the printer or laser 
unit, follow the procedures specified in this manual and there will be no hazards from 
the laser.