Figure 6-1 Measuring The Dc Voltages (Test Points) - Tektronix Phaser 440 Service Manual

6
Troubleshooting
6-4 Phaser 440 Color Printer
5. DC Output: With the VOM set to measure DC voltages, measure for
+5 VDC and +24 VDC. The following illustration shows the test
points. Be aware that the +24 VDC supplied to the motors is supplied
directly through the cover-open safety interlock switches. Refer to
Appendix C, "Wiring Diagrams" for more details on other voltage test
points.
6. Thermal head voltage: With the VOM set to measure DC voltages,
measure for the thermal head's VH voltage at its power harness.
Refer to the topic "Power supply thermal head voltage (VH) check"
on page 9-5.
7. Engine fan : Ensure that the power supply fan runs while the printer
is turned on. The fan blows into the card cage (toward the image
processor board).
If you do not measure DC voltages, proceed to the next step "Inspecting the
power supply fuses."
If the +5 VDC and +24 VDC voltages measure correctly, but the printer does not
operate correctly, then proceed to the procedure "+24 VDC safety interlocks."
CN 5
Pin 15 +5 VDC

Figure 6-1 Measuring the DC voltages (test points)

2 2
2 1
Pin 10 GND
Pin 2 +24 VDC
2
1
9015-33