Measuring Power Supply Voltages; Figure 6-1 Measuring The Dc Voltages (Test Points) - Tektronix Phaser 300i Service Manual

Measuring power supply voltages

1.
Turn off the printer and unplug it from its power outlet.
2. AC Input: With the VOM set to measure AC voltages, measure for
power being supplied to the printer. It should measure between 87 to
128 VAC (115 VAC nominal) or 174 to 250 VAC (220 VAC nominal).
Ensure the 115/220 VAC line select switch is correctly set.
3.
Remove the rear access cover and the cabinet top to access the power
supply wiring harnesses.
4. Override the rear cover interlock switch by closing it with a folded
sheet of paper.
5.
Plug in the printer and turn it on.
DC Output: With the VOM set to measure DC voltages, measure for
+5, +12, -12 and +40 VDC. The following illustration shows the test
points.
GND
on
pin 3
Measure
+5 VDC on
pins 19, 20, and 21

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

6. Printhead voltage: With the VOM set to measure DC voltages,
measure for HV+ and HV-. On Pin 1 is HV+ which should be between
68 to 102 VDC. On pin 5 is HV- which is between about -68 to -102
VDC. Pin 3 is ground.
7.
Power supply fan : Ensure the power supply fan runs while the
printer is turned on. The fan blows out of the supply.
1
2
3
4
5
.
Measure +40 VDC on
.
pin 10, 11, and 12
.
.
Measure -12 VDC on
pin 22
Measure +12 VDC on
pin 24
Service Manual
6
Troubleshooting
8818-41
6-5