Do System Tests to Identify Defective Components
94 810430 Troubleshooting Guide Powermax65/85/105 SYNC
Test 5 – Flyback circuit (DC minor voltages)
Use this test if you get a 3-00-0, 3-42-n, or 3-43-n fault code. Minor voltages are missing.
The flyback circuit is the source of minor DC voltages for the internal fan, solenoid valve electronic
regulator, and power PCB.
A short-circuited fan can prevent you from getting correct voltage measurements in this test. If
nothing shows on the LCD screen after the plasma power supply is set to ON (I), this can be an
indication of a short circuit in the fan.
1. Set the power switch on the plasma power supply to OFF (O), and disconnect the power cord.
2. Remove the plasma power supply cover and the component barrier.
3. Connect the power cord to the power source, and set the power switch on the plasma power
supply to ON (I).
4. Measure the voltages for the internal components shown in Table 7 on page 95. Refer to
Figure 19 on page 97.
WARNING
ELECTRIC SHOCK CAN KILL
The plasma power supply contains dangerous electric voltages that can seriously injure or
kill you.
Use extreme caution if you do service or maintenance work on a plasma power supply
when it is connected to an electric power source and the outer cover or panels are
removed.
NOTICE
Do not use -VBUS to attach to ground. Doing so could make the plasma power supply unserviceable.
Use the ground screw on the heatsink. Refer to How to attach to ground on page 76.