Spindle speed control

The spindle control board provides the three phase power control for the spindle drive motor. 24VDC powers the board, and is indicated with the red power LED. Spindle RPM signals are 5VDC supply, common (5VDC return) and a variable voltage signal that setts the RPM.

Using a volt meter set for DC readings, you can check the supply voltages, especially if the LED is not powered. You can then check the 5VDC /Common voltage. With a valid spindle speed set in PathPilot RPM field. click FWD, the FWD indicator will light. Check for a voltage on the connector containing the yellow wire. It should have a voltage between 0 and 4, dependent on the RPM you entered. 20,000 RPM will be around 4VDC. If this signal is present, the problem may be the board, spindle motor, or the wiring to the spindle motor. If there is no signal present, use a short piece of electrical wire to briefly connect the red and yellow wires. Be sure the router cover is closed before performing this test! If the jumper test works, inspect the CL cable back to the main control board.