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These ATCs use an ATC control board (powered through the 68 Vdv DC-BUS) and power drawbar control board (powered through a 12 Vdc daughter board via the DC-BUS). These two communicate by an RJ11 cable (DB3). Finally, the power drawbar control board has an additional RJ11 (DB1) that is connected to the VFD so they can commutate whether the spindle is running or not.
Reseat the USB
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Cable
Reason: The ATC USB is unplugged
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Inspect to see if there are lights on the ATC control board.
Measure 65 Vdc at DC-BUS (503+ and 504-) ad then on the ATC control board.
Measure 12 Vdc from the daughter board at the DC-BUS (501- and 502+) and at the power drawbar control board.
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Replace the DB3
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Cable
Reason: The DB3 is disconnected or damaged.
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