[SOLVED] M4 not spinnig

[Qvims]

Hi
So I've had the Crazyflie for a couple of weeks now, and I have still not been able to fly it yet. When I first got mine, I managed to solder M4 the wrong way, No problem I'll just de-solder it. Well I did and it didn't go so well. When I finally managed to solder M4 back the right way, I noticed that It wasn't spinning. I have tried resolder it many times and the mess just gets bigger and bigger.

This could just be a simple shortage between +and -, but i'm not sure anymore. I'll attach some pictures so you guys can be the judge for yourself.

Pics:
http://imgur.com/a/CeDa1

Thanks again!

[marcus]

Hi,

It looks like there might be a short next to one of the vias next to the transistor (see attached image). Do you have any flux to clean up the soldering?

[Qvims]

I have tried using some desoldering braid to clean it up. But to me there doesn't seem to be a short there, the picture might throw you off a bit. I'll try to clean some more nonetheless.

[foosel]

Do you have a multimeter? You could use one to measure for a short.

[yoozername]

I'm also having a problem with M4. It spins, but seemingly not as fast as the others, because there's a huge bias in that direction. Is this a wider problem or just bad luck?

EDIT: my problem was due to bad mappings (using Ouya controller).

[tobias]

I have tried using some desoldering braid to clean it up. But to me there doesn't seem to be a short there, the picture might throw you off a bit. I'll try to clean some more nonetheless.

Any update on this. Did you manage to fix it?

[Qvims]

Sorry for a really late replay (vacation and stuff), But no I did not manage to solve the issue. I did try to use a multi-meter to measure and see if there is a short between the two contacts, and there dose NOT seem to be. Is there anywhere else I could measure to check for problems?

[tobias]

The connection between the pad and the transistor might have been damaged, but there are workarounds if that is the issue. If the motor is soldered to the pads can you measure the resistance between the single leg on the transistor (within the red circle in your pic) close to the round motor pad to the square motor pad. It should read about 2 ohms. I'll try to illustrate this better with a picture when I get home.

[Qvims]

Motor 4 is currently not soldered to the pads. The other motors has about 2,3 ohm in resistance. M4 has 1,7 in resistances but again, the motor is not connected.

[tobias]

Can you measure if there is a connection (~0 ohm) between the M4 round motor pad and the single leg on the transistor?
Then measure between the M4 square pad and M3 square pad, it should also be ~0 ohm.
You can also measure the diode if your multimeter has that capability. Put it in diode measurement mode and place the positive (red) probe on M4 round pad and negative (black) on the M4 square pad. It should measure around 0.25V.

If they all pass then the connections are OK but I don't think they are. What you can do as a workaround is to solder the M4 black wire directly to the transistor leg if that connection is broken. You can also solder M4's white wire to M3's square pad.