Verifying Power Supply Operation; Measuring Power Supply Voltages - Tektronix Phaser 360 Service Manual

6
Troubleshooting

Verifying power supply operation

6-6 Phaser 360 Color Printer
Required tools
TORX T-20 screwdriver
Volt-ohm-meter (VOM)
The power supply is divided into two sections: the AC section used for heaters
and the DC section for control logic, printhead drivers and motors. Verifying
the power supply involves five steps:
Checking for proper AC voltage.
Inspecting the power supply fuses.
Testing DC output voltages.
Testing for a shorted motor or solenoid driver which shuts down the
power supply.

Measuring power supply voltages

Warning AC line voltages are present on the power supply and possibly in
the printer, via the heaters, while the printer is plugged into an AC
outlet, even if the power switch is off.
1. Turn off the printer and unplug it from its power outlet.
2. AC Input: With the VOM set to measure AC voltages, measure the
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).
3.
Remove the right side cabinet panel to access the wiring harnesses
plugged into the print engine control board.
4. Plug in the printer and turn it on.
5.
Using the Tektronix DMM 252/254 set for Hz (also, press the blue
button), measure the AC sense test point. If the power supply can
sense the AC input voltage, you should measure ~8.2 kHz for
115 VAC, or ~16.4 kHz for 220 VAC. The range varies from 6 kHz for
87 VAC to 17 kHz for 250 VAC.
6. AC Output: FuseF1 is the AC input fuses for the DC section of the
power supply. If it opens, the power supply does not function.