Xerox Phaser 790, Service Manual

Page: 8 / 653

10/00
vi Phaser 790/DocuColor 2006
Initial Issue Introduction
Voltage Measurement and Specifications
Measurements of DC voltage must be made with reference to the specified DC Common,
unless some other point is referenced in a diagnostic procedure. All measurements of AC volt-
age should be made with respect to the adjacent return or ACN wire.
Logic Voltage Levels
Measurements of logic levels must be made with reference to the specified DC Common,
unless some other point is referenced in a diagnostic procedure.
DC Voltage Measurements in RAPs
The RAPs have been designed so that when it is required to use the DMM to measure a DC
voltage, the first test point listed is the location for the red (+) meter lead and the second test
point is the location for the black meter lead. For example, the following statement may be
found in a RAP:
There is +5 VDC from TP7 to TP68.
In this example, the red meter lead would be placed on TP7 and the black meter lead on TP68.
Another example of a statement found in a RAP might be:
There is -15 VDC from TP21 to TP33.
In this example, the red meter lead would be placed on TP21 and the black meter lead would
be placed on TP33.
If a second test point is not given, it is assumed that the black meter lead may be attached to
the copier frame.
Table 1 Voltage Measurement and Specifications
VOLTAGE SPECIFICATION
INPUT POWER 220 V 198 VAC TO 242 VAC
INPUT POWER 100 V 90 VAC TO 135 VAC
INPUT POWER 120 V 90 VAC TO 135 VAC
+5 VDC +4.75 VDC TO +5.25 VDC
+24 VDC +23.37 VDC TO +27.06 VDC
Table 2 Logic Levels
VOLTAGE H/L SPECIFICATIONS
+5 VDC H= +3.00 TO +5.25 VDC
L= 0.0 TO 0.8 VDC
+24 VDC H= +23.37 TO +27.06 VDC
L= 0.0 TO 0.8 VDC