My Siemens 610 axis drive (6SC6140 X-axis drive) faults out after about 15 seconds from power up. The 'T' test point on the 'N' board counts up to about 9.3 volts, then the drive faults out with the center LED on the 'N' board on. I can disconnect the DC bus and the motor leads from the power board (6SC6140 board), leaving only the ribbon cable, and it still faults out the same. I can swap with another 6SC6140 axis board and the problem moves with the suspect board. I need advice and or a component level schematic of the 6SC6140 board.