No power on Motor Shield v2 without VIN jumper

[fjeske]

Hi:

I have a v2.3 Motor Shield attached to a Arduino UNO, Adafruit's NEMA 17 stepper and 12v 2A wall power supply. Everything works OK with the V2 library with the exception that the motor shield doesn't get any power UNLESS the VIN jumper is installed. Neither USB nor 12v works without the jumper and the motor noticably improves torque with 12v. This is the opposite to what I read on the support site.

Is there a short somewhere or just a bad soldering job? I've tested the continuity of all the soldered pins with an Ohm meter and think they're all OK. Since it works, do I care?

Felix

[adafruit_support_mike]

Could you post another photo of the shield from a side-angle please?

The shot above is nice and clear, but doesn't show the shapes of the solder joints at the headers.

[fjeske]

Side view image attached.

[fjeske]

Since you're suspecting the soldering, I touched up each one again so they don't all look like Hershey Kisses and now look more like curved funnels. Didn't change a thing.

[adafruit_support_mike]

That's how they should look, and from the photos the joints at Vin and GND needed to be reflowed.

Do you have a separate power supply screwed into the power terminals on the Motor Shield? That's the case where you remove the VIN jumper.

[fjeske]

No wires screwed in, just a DC plug as shown in pic #1. So for a plug like this, VIN stay in? Again, fine, it's working with it.

[adafruit_support_mike]

Yes, the motors receive power from the DC barrel jack when you have the VIN jumper connected.

[adafruit_support_bill]

If you want to supply power directly to the motors, independent of the Arduino power, you need to use the external power terminal as described here: https://learn.adafruit.com/adafruit-mot ... ing-motors