Burning Issue

[Bill Arnold]

I've been looking for information online in stepper driver forums for an issue that came up, so here I am in a woodworking forum hoping one of you geeks can assist.

I'm using DRV8825 drivers. The issue is related to R4 in this diagram:




When I apply 12VDC power to the RAMPS1.6 board with a driver plugged into its socket, R4 immediately starts burning, so I disconnect power. The only thing attached to the board is the Arduino and 12VDC power; no power applied to the Arduino, except via the RAMPS. The same thing happens on a second set of boards with the Arduino powered via USB and 12VDC applied to the RAMPS.

The strange thing about this is I did not have this issue on a RAMPS/Arduino set that I was installing on my 3D printer. I bought a second set of boards to be able to investigate an issue with the display fading out with drivers installed on the first set.

With all this happening, I'm concerned about blowing up more drivers. Any thoughts?

 

[Darren Wright]

Looks like it is part of a voltage divider. My first check would be to make sure you've got the board the correct way and not upside down, second would be to check the logic power coming to that driver is in the 3.3 to 5 v range rather than 12v. The pins catercorner to the 12 v should be the driver/step pins and would be logic level power.

 

[Darren Wright]

Looks like logic level could come in on that pin7 (Fault) and pin 8 (ground), check that the voltage is within range on it.

 

[Bill Arnold]

Thanks for the leads, Darren. I got re-directed to some lawn activities and will work on this more Wednesday.