Xerox 6250N Service Manual - Page 86

6. Before measuring voltages make sure the printer is switched ON, the Imaging Unit and the paper trays are in place, and the interlock switches are actuated, unless a troubleshooting procedure instructs otherwise. 7. All voltage values given in the troubleshooting procedures are approximate values. The main purpose of voltage readings is to determine whether or not a component is receiving the correct voltage value from the power supply and if gating (a voltage drop) occurs during component actuation. Gating signals may be nothing more than a pulse, resulting in a momentary drop in voltage that may be difficult or impossible to read on the average multi-meter. 8. When a troubleshooting procedure instructs you to replace a non-spared component and that component is part of a parent assembly, you should replace the entire parent assembly. 9. Ensure that you are using a supported media size and type, refer to "Media and Tray Specifications" on page 1-14. Voltage Measurements 1. Power and signal grounds are connected to the frame ground. All circuit troubleshooting can be performed using the metal frame (chassis) as the grounding point. To locate connectors or test points, refer to the section "Plug/ Jack Locator Maps" on page 10-2 or "Wiring Diagrams" on page page 10-12 for more information. Unless otherwise specified, the following voltage tolerances are used within this section: Stated +3.3 VDC +5.0 VDC +24.0 VDC 0.0 VDC Measured +3.135 to +3.465 VDC +4.75 to +5.25 VDC +21.6 to +26.4 VDC Less than +0.5 VDC Error Messages and Codes 3-5