Quadcopter Short Circuit but No Continuity

• #2

Hi all,

I need some help. Recently, I've been trying to build my first quadcopter, however have encountered a few problems, which I have been struggling to solve.

I'm using a Naze32 flight controller, and I have been using clean flight to calibrate it. The Naze32 board works, at least the gyro does when plugged into my PC. When I proceed to calibrate the motors with throttle etc, my PDB burns out as soon as I plug the battery into the circuit. My initial thoughts were perhaps a short circuit? I'm relativity confident all my components are rated OK (ESC's rated higher than my motors etc etc). On further evaluation, I noticed my ESC's do not have BEC integrated, and all four are powering the Naze32 Board. Could this be the issue?

Are there some common newbie problems that can occur? Am I missing something extremely obvious?

Best regards

Steve

Give some more info on the power system, like 3S LiPo, and what are the ESCs designed in regards to voltage. Also what do you mean by shorting out? Usually a short with a LiPo involves fire, smoke and some melted metal near the short.

ESCs usually have a Diode connected across the positive and neutral which acts as reverse polarity protection; if you have reversed polarity it shorts at the diode before it gets further in the ESC.

• #4

Do you have a continuity tester? I'd suggest checking to see if the solder on one of the ESc's wires is touching something it shouldn't. A lot of those PDBs built into the frame are close enough to short if you use too much solder in a joint. I'd suggest checking that and perhaps de-soldering the ESCs and testing the PDB it'self to see if it has some manufacturing error or short that you missed.

• #5

I noticed my ESC's do not have BEC integrated, and all four are powering the Naze32 Board. Could this be the issue?

If there is no BEC there is no powering.

• #7

I need to purchase a new frame (PDB) anyway (Its a mess from repairs etc), but I shall try the continuity test on all my solders before advancing. I shall keep this thread open and updated if that's okay in case I still have the issue?

^^ Also, I will be changing my ESC's to an integrated BEC, and follow some tutorials online to help me wire that up to the flight controller correctly.

Thanks!

The BEC just steps battery voltage down to a voltage the flight controller and other subsystems can use (usually 5v). You could buy a BEC seperate to avoid getting any more ESCs. Confused on what you mean by short and the PDB burning out though. Is there heat, smoke, or a fire?

• #10

These are great thanks! So i'm guessing the BEC/UBEC doesn't have anything to do with this shorting problem?

So i assume its shorting, it may be something completely unrelated. But it does show the typical signs of a short. When I plug in my battery, there is a quick spark/noise between the connections, very soon after, smoke starts to come from the PDB, around where an ESC is soldered (No fire, unsure about heat but id assume there is. I wasn't too keen on putting my finger to it to feel it after it happened). The copper tape breaks, thus breaking the circuit. The photo below you can see the postie terminal for the battery, and the broken copper tape above & right of it. This didn't occur anywhere else.

Must be a smaller short, but if there is smoke then you're right. Does your frame use any carbon fiber? Most people forget that it is somewhat conducive. Or perhaps a wire is clamped between two things like the arm and bottom plate. These are just guesses, you should be able to open it up and find the damage.

• #12

... Glad to hear you got it sorted out
Next comes more fun getting the quad nicely tuned by messing with your PIDs

carterpongle90.blogspot.com

Source: http://quadcopterforum.com/threads/my-first-quadcopter-short-circuit.12780/