Control Board Heat

Is it normal for a control board to become very warm (almost hot to the touch) within minutes of power up?
Trying to determine whether I’ve damaged my board by soldering in the leads for spindle control. The controller is working normally (though the spindle control isn’t- it’s only putting out about 320mV instead of 5v given the spindle-on command). I’ve done the spindle upgrade successfully twice before on newer boards… this one is not going so well.

I should clarify my question: Is it normal for the controller to get hot quickly when it’s disconnected from the heat sink (just powered on, no milling). I had it pulled out to check the soldering and test voltage when I noticed the heat.

No, it’s not normal.


When I upgraded to the Bit Runner I removed the original large heat sink because the new cover screws are offset on each side and the original had holes in the center of each side. The instructions never mention about the heat sink. There was thermal tape on back of the board and I added the tape included in the upgrade kit. The board is mounted on standoffs that space the control board about a 1/4 inch away from the rail on my XXL (3 and maybe XL are on gantry). So with no way to disparate heat the board may heat faster. Connect the board to the machine and then see if it makes any difference. The original had a massive heat sink so it was there for something.

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.