11.Remove plug J30 from the protection board. See Figure F.1 for location of the board and plug J30.
WARNING
ELECTRIC SHOCK can kill.
With the input power ON, there are high volt- ages inside the machine. Do not reach into the machine or touch any internal parts.
12.Turn input power ON.
13.With the volt/ohmmeter, check for 24 VAC between plug J12 - pin 2 and pin 4.
A. If 24 VAC IS present, go to step 14.
15.Remove plug J26 from the protection board. Attach a 150 ohm resistor between plug J26 - pin 1 and J26 - pin 2 (the J26 plug, not the header on the control board).
16.Replace plug J12 into the display board,
WARNING
ELECTRIC SHOCK can kill.
With the input power ON, there are high voltages inside the machine, including the protection board. Do not reach into the machine or touch any internal parts.
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Return to Section TOC
Return to Section TOC
Return to
Return to Master TOC
Return to Master TOC
NOTE: A voltage of 5 to 10 VDC is normal between these pins without the D to E jumper installed in the
B.If 24 VAC is NOT present, check for 24 VAC between plug J33 - pin 4 and pin 1. See the Trigger Circuit Wiring Diagram,
Figure F.50.
C.If 24 VAC IS present between plug J33 pin 4 and pin 1, check the continuity and integrity of leads #371, 374, 102C, 105B, 296, and 293 and their associated pin con- nectors. See the Trigger Circuit Wiring Diagram. If the continuity checks are good, check the square wave TIG protec- tion board by checking the continuity through the following pins. See the Trigger Circuit Wiring Diagram, Figure F.50.
Plug J92 - pin 6 to plug J93 - pin 5. Normal resistance is 4 ohms.
Plug J92 - pin 3 to plug J93 - pin 7. Normal resistance is 4 ohms.
If the square wave TIG protection board is good, then the protection board may be faulty. Replace the protection board.
D.If 24 VAC is NOT present between plug J33 pin 4 and pin 1, check Auxiliary Transformer #1, the 5 amp circuit breaker, and the associated wiring. See the Trigger Circuit Wiring Diagram, Figure F.50.
14.Turn input power to the machine OFF and perform the capacitor discharge proce- dure.
17.Turn input power ON. The LCD display will read: ERROR: S.L. NOT INITIALIZED. Disregard this; the test can still be per- formed.
18.Remove the jumper between pins D and E of the
19.With the volt/ohmmeter, measure the volt- age drop across the 150 ohm resistor between J26 - pins 1 and 2. With the jumper removed, the reading should be zero volts (NO voltage drop).
20.Replace the jumper between pins D and E of the
A.If 2 VDC is NOT present, check the conti- nuity and integrity of leads #262 and 261 and their associated pins and connectors. The display board may be faulty
B.If 2 VDC IS present across the resistor, the control board may be faulty
21.Turn input power to the machine OFF and connect the five leads to the main contac- tor. Connect all molex plugs to the PC boards and replace the cover with two sheet metal screws. Install the machine case sides, top, handle, and lift bail rubber gasket.
