Broke Front Arm & Replaced - Now I ran into another issue..

[Scherping19]

Hi All -

Recently, my Mavic Pro went into Atti mode and I crashed into a building (I'm not very experienced). The front left arm was broke. I purchased a replacement arm, disassembled my Mavic Pro, soldered the wires to the board and reassembled. I did have some difficulty soldering the wires to the board, especially the two smaller wires (is there a special solder I need?). It seemed as if the solder wouldn't adhere properly but before I reassembled i made sure all connections were tight. I powered the Mavic Pro up and everything seemed normal, lights blinked, propellers moved back and forth, etc. When I launched the aircraft it seems like it went in to full speed, and it spun around on the ground, more leaning on the arm that I just replaced; it wouldn't ascend into the air. No warnings or anything came up. All four motors were turning. Is it supposed to be re calibrated with the new arm? What can be done to fix this issue? Any help is appreciated!

Thanks,

 

[Scherping19]

Thanks Zaceshighz. Yes, they are in the correct spot (I took a picture before hand and compared to opposing side). The motor wires are away from the compass, they are routed almost the same way before I replaced the arm. As far as compass calibration, would a warning display if it was not calibrated? I'd hate to try to take off again and have the drone crash again or break another propeller.

Have you soldered anything on your drone? Is there a special solder that is needed? I was able to un-solder them very quick and easy but when it came to soldering it was difficult. The solder wouldn't adhere to the board properly but i was able to get them to stick eventually but it doesn't look as clean as factory.

 

[Scherping19]

Thank you. I thought the motor wire solders weren’t too bad. I was more concerned about the two small wires, for the LED possibly?

How do I start the propellers without the aircraft lifting off? Sorry, I’m still fairly new to this. I’ve had it for about a month and flew it maybe 4-5 times.

 

[Spy808]

Seems to me like the motor is spinning the wrong way if the arm ü replaced is being leaned upon... Wire could be on backwards...

 

[lolo780]

Seems to me like the motor is spinning the wrong way if the arm ü replaced is being leaned upon... Wire could be on backwards...

This. Check your rotation direction on the new arm.

 

[Dragonfly]

It sounds like you have connected the motor wires up to the board wrong and the motor is spinning in reverse pinning that leg to ground and rest of quad is rotataing round it on lift off.
A) check prop /motor turning correct way.
B) recheck wire/solder placement on board. They should be mirror image off other side not same as other side. i.e if white wire is on the inside pad then it should be on inside pad for both black center and grey on outside for both.
Other 2 small wires are for LED in leg and longer small wire goes to back board for aerial from arm leg.

Also when resoldering on Mavic as the solder is 100% lead free either fully remove and resolder with 60/40 5core or add a bit of 60/40 5core when desoldering and resoldering joints.
This adds a bit of flux and lead to transfer heat and flow the lead free solder quickly for smooth clean joint.

 

[Scherping19]

It’s official, I’m an idiot. You all were correct; I wired the black and the tan on opposite ends. I told myself to to look at other side when I did it but that’s what happen when you try to repair at midnight [emoji23]. Thanks everyone for the help. It is much appreciated. Now I need to work on my solder skills if this happens again ha ha.