Hypertherm Powermax30 XP Service Manual - Manual (Page 78)

78 Powermax30 XP Service Manual 808150 Revision 1
5 – Troubleshooting and System Tests
Test 3 – VBUS and voltage balance
Test the power board to verify that the circuits are balanced. The test points are labeled on the back of the power board,
as are the voltages and positive and negative capacitor terminals. See
Figure 18 on page 79 for locations of test points.
1. Set the power switch to OFF (O), disconnect the power cord from the power source, and disconnect the gas supply.
2. Remove the power supply handle and cover. (See Remove the power supply cover on page 88.)
3. Remove the component barrier. (See Remove the component barrier on page 90.)
4. Reconnect the electrical power.
 Carefully connect the test hooks to the edges of the holes in the power board so that the
hook makes contact with the ring on the back side of the power board.
Figure 17
CAUTION!
Do not use a multimeter with test leads. This can cause a short-circuit between the BUS and the
heatsink. Use test hook leads instead, and attach them to the test point loops.
WARNING!
ELECTRIC SHOCK CAN KILL
Use extreme caution when working near live electrical circuits. Dangerous
voltages exist inside the power supply that can cause serious injury or death.
See the WARNING! on page 58 before proceeding.