Tweco 81 with SL100SV - Manual (Page 87)

Manual 0-4641 5-23 SERVICE
5
G. No arc or intermittent arc in torch; Gas flows; AC , GAS , and DC indicators ON; TEMP indica-
tor off
1. Gas pressure set incorrectly (too high)
a. Reset gas pressure per pressure setting label on power supply.
2. Oil/moisture in air lines
a. Purge system. If problem corrected, add filters in line with air source.
3. Incorrect torch parts
a. Inspect the torch parts; replace as needed.
4. Faulty leads
a. Check torch leads continuity.
5. Faulty torch
a. Check torch.
6. Faulty connection of wire #58 or 62 to Pilot Board
a. Check wiring connection. Refer to the System Schematic in the Appendix. Connections should be:
• Wire #58 to Pilot Board terminal E58
• Wire #62 to Pilot Board terminal E62
If wires 58 and 62 are not connected to the proper terminals, replace the Pilot Board.
7. Faulty Main PC Board
a. Check for approximately 12 vdc at TP4 to TP1. If less than 2 vdc, replace the Main PC Board.
8. Faulty Logic Board or Faulty Pilot Board
a. Install a jumper between wires 58 and 62 on Pilot Board and retry piloting. If torch pilots with jumper installed, replace
Pilot Board. If torch does not pilot, replace Logic Board.