Inspecting The Power Supply Fuses; Figure 6-1 Measuring The Dc Voltages (Test Points) - Tektronix Phaser 550 Service Manual

6
Troubleshooting
6-4 Phaser 550 Color Printer
4. DC Output: With the VOM set to measure DC voltages, measure
voltages at CN852, CN854, and CN855 for +5 VDC, +12 VDC and
+24 VDC. If the voltage is not correct, replace the power supply. The
following illustration shows the test points.
Power supply
CN 854
Pin 6 - GND
5 - GND
4 - GND
3 - +5 V
2 - +5 V
1 - +5 V
CN 852
Pin 5 - +24 V
4 - +24 V AB
3 - GND
2 - +5 V B
1 - GND
CN 855
Pin 1 - GND
2 - +12 V NS
3 - –12 V NS
4 - NFSRCTL
5 - GND
6 - GND
7 - + 5 V A
8 - CFMPERR
9 - NOOPN1
10 - NESM

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

If DC voltages are not being output by the printer, proceed to the next step,
"Inspecting the power supply fuses" on page 6-5.
If the +5, +12 and -12 VDC voltages measure correctly, but the printer does not
operate correctly, then proceed to the topic, "Safety interlocks."
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