Thermadyne Thermal Dynamics PAK MASTER 50XL, Service Manual

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SERVICE TROUBLESHOOTING 16 Manual 0-2587
D. Main Arc Test
Press the Torch Switch to establish a pilot arc.
Bring the torch to within 1/8"-3/8" (3.2 - 9.5 mm) of the
workpiece to establish the main cutting arc, and note the
following:
• Main cutting arc initiates
• Pilot arc turns OFF
This completes the Main Arc Test. If the above are all
correct then the equipment should be operating properly.
If problems still persist then contact Technical Services.
If the above does not function as noted then note the
symptom and proceed to Section 4.08, Main Arc Prob-
lems.
4.06 Main Input and Internal Power
Problems
Locate your symptom below:
A. Main power line fuses blow as soon as main
disconnect is closed
1. Input power cable installed incorrectly
a. Refer to Operating Manual 0-2586, Section 3.07
and connect input cable
2. Input voltage selection incorrect for the main input volt-
age
a. Refer to Operating Manual 0-2586, Section 3.06
and select proper input voltage
3. Faulty Input PC Board
a. Test Input PC Board per Section4.09-D; repair
as necessary
B. AC indicator on front panel of power supply is
OFF
1. Front Panel ON/OFF switch in OFF position
a. Place switch to ON position
2. Main power disconnect not closed
a. Close main power disconnect
3. Main power line fuses blown
a. Replace main power line Fuses
4. Defective input power cable
a. Replace input power cable
5. Improper input power line connections inside Power
Supply
a. Refer to Operating Manual 0-2586, Section 3.07
and correct if needed
6. Fuse blown inside Power Supply
a. Replace internal Fuse (1 FU)
7. Voltage selection plug connected incorrectly
a. Refer to Operating Manual 0-2586, Section 3.06
and correct as needed
8. Faulty Auxiliary Transformer (refer to Appendix XI,
36 VAC Circuit Diagram)
Measure for 36 VAC on Logic PC Board from J1-1
to J1-5.
a. If voltage is not present, replace the Auxiliary
Transformer
9. Faulty Logic PC Board (refer to Appendix XI, 36 VAC
Circuit Diagram)
Measure for 36 VAC on Logic PC Board from J3-1
to J3-3.
a. If voltage is not present, replace the Logic PC
Board
10. Faulty ON/OFF switch (refer to Appendix XI, 36 VAC
Circuit Diagram)
Measure for 36vac on the Logic PC Board between
J3-2 to J3-4.
a. If voltage is not present replace the ON/OFF
switch
11. Faulty Logic PC Board (refer to Appendix XI, 36 VAC
Circuit Diagram)
Measure for 36 VAC on Logic PC Board from J4-2
to J4-6 or J4-4 to J4-8.
a. If voltage is not present, replace the Logic PC
Board
12. Faulty ribbon cable
Refer to Appendiv XI, 36 VAC Circuit Diagram
and check for continuity on thepins.
a. If any line between pins is open, replace the
ribbon cable