Geeetech

Dear friend,
you'd better check the due first,make sure it is ok.Tips:you'd better don't connect the other board or module

I did. and I reported the results.

what is the next step in getting this resolved. I am getting frustrated.

1.if you use due+fd（fd not use power），and it does not work，the fd maybe broke
2.if you use due+fd+stepper motor+ other，the current is not enough

It sounds like the FD is broken then. you can send another if you like, or arrange for a refund for both my FD and Due.

As long as it took to come to an answer, I think I would rather send it all back. This is for my 5th printer, and I had no idea it would be this much trouble to evaluate the RAMPS-FD/due combo.

1.first，you should set the multimeter like img 4021 2.then test these point +5v（RED Probe）& gnd(black Probe) and +3.3v（red Probe） & gnd（black Probe）。 if If the multimeter tweet，the FD is short with power

I get 7V where it should be 5V, and nothing at all on the 3.3V

i meens that test the power and gnd。are they short？NOT test the voltage

Ok. Is there something else you want me to do? or are you ready to arrange a return?

There is nothing for the time being。if it is short，there is short in capacitance。if not，the ic maybe broken

Since you diagnosed a bad FD, I ordered a new one. The new one arrived and it does the same thing as the last one. (no USB communications when the FD is powered).

Any advice?