Weak Motor?

[Kremit]

I've built a 250 drone, everything seems to be working. I've done a 24" hover, moved around at very low speeds, things seemed to be working, but then the coptor started diving to the front left. I'd be in a hover, and bang, it'd on the ground. The last time, it broke the prop, so I replaced it. With the prop replaced, yes, it's the right direction, I arm it, the props start spinning, and as soon as I try to give it throttle, it flips over on motor 3. Holding it in my gloved hand, I can throttle it up and the motor obviously cuts out under load. Is it possible to have a motor 'go bad' like that? I checked all the ESCs, the solder connections and wiring.
I'm stumped... short of replacing the motor, I'm not sure what to do.

 

[holtneil]

Hi mate an easy way to check is to move the motor so it's on a different esc ,if it still does it then it's the motor

 

[Dugdog47]

What kind of motor? Flight control board? I had a Chinese clone of an omnibus f4 board start doing this and I thought it was the cheap racer star motors, but then the board started smoking and then it stopped working all together. I replaced the board but kept the motors and the quad still flies great.

To sum up my post, a poor quality fight control board can cause your issue.

 

[mozquito1]

Go into blheli suite & check all four esc's have the same min & max endpoints.
Except for some littbee I use the same esc on all build. But sometimes even though the same they come with a few setting slightly not the same. I had a motor not kick in till 70% throttle till I brought the min endpoint down to 20,same as others.
It may be this. If not try what holtneil says.