Manual 0-2972
4-15
TROUBLESHOOTING
4.10 Test Procedures
The test procedures in this subsection are referenced in
the troubleshooting section.
A. Safety Precautions
1. Significant DC Voltage exists after removal of input
power. Allow two minutes for discharge time. Voltage
measured on input capacitors must be zero before per-
forming service on the power supply.
2. Do Not touch electrical components with any part of
the human body when power is applied.
3. Keep away from any moving parts.
4. Hot surfaces can cause severe burns. Allow equip-
ment to cool before servicing.
5. Electrostatic discharge can damage printed circuit
board assemblies. Transport printed circuit boards in
proper antistatic shielded packages. Use proper
grounding techniques with wrist strap before handling
printed circuit boards.
6. Misaligned plugs can cause printed circuit board dam-
age. Be sure plugs are properly aligned and completely
seated.
7. Excessive pressure can damage printed circuit boards.
Use only minimal pressure and gentle movement when
disconnecting or connecting printed circuit board
plugs.
B. Opening Power Supply Enclosure
The cover of the Power Supply must be removed to gain
access to the input power connections.
WARNING
Disconnect primary power at the source before as-
sembling or disassembling the Power Supply, torch
parts, or torch and leads assemblies.
1. Remove the upper screws securing the cover to the
main assembly.
2. Loosen, but do not remove, the lower screws.
NOTE
There is a ground wire attached from the cover to
the main body of the unit.
3. Carefully lift the cover off the unit, and remove the nut
securing the ground wire to the side panel.
4. Re-install the cover by reversing the above steps.
Art # A-03939
Lower
screws
Ground wire
Lower
screws
Upper
screws
