Thermal Dynamics Pak Master 75XL Plus, Service Manual

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TROUBLESHOOTING 4-6 Manual 0-2747
5. Faulty Wiring or Logic/Gate PC Board
Check for DC voltage from Logic/Gate PC Board
J2-13 to TP1 (GND)
• If less than a volt, replace Logic/Gate PC Board
A-02546
J2
TP1 (GND)
Logic/Gate PC Board
G. Arc in torch without pressing torch switch; AC
indicator ON; Gas flows; GAS and DC indicators
ON
1. Faulty torch switch
a. Refer to appropriate Torch Instruction Manual
and check continuity.
2. Faulty torch leads
a. Refer to appropriate Torch Instruction Manual
and check continuity.
3. Faulty Pilot PC Board
Remove power from power supply. Disconnect
J12 and J13 from the Pilot PC Board.
Check for an open between J12 pin 1 to J12 pin 3
on the Pilot Output PC Board.
a. Replace Pilot Output PC Board if conti-
nuity is present.
A-01399
Pin 3
J12
Pin 1
Pilot Output PC Board
To
p
4. Faulty Logic/Gate or Pilot PC Board
Check for DC voltage from Logic/Gate PC Board
J5 pin 8 to J5 pin 9.
a. Replace Logic/Gate PC Board if voltage is ap-
proximately 12 vdc.
J2
A-02547
Logic/Gate PC Board
J5