Newb, get me off the ground!

[VolcomSurfer]

Okay, so I have a friend that was flying and the thing just took off to one side and dropped out of the sky. It fell on some rocks and got a bit of ocean spray on it. He ended up aquiring another one and just put this one to the side. I asked him if I could have to since he was just going to trash it, he agreed.

Now help me get this thing going. Only 1 motor seems to work at full potential, 1 doesn't move at all, 1 is kinda jumpy then it'll kick in, and the other is slow as hell. I opened it up and didn't find any corrosion around any of the connections. The battery is dead I believe (keeps flashing red and beeping), the meter says it's at 5V. So I need to go to his house to charge it. I was going to see if there was voltage going to the motors first. What other troubleshooting can I do? At power on, the cycle doesn't show any errors.

I'm not sure what kind of maintenance, if any, he's done with this thing. I was assuming that the motors just hit the bed, so I was going to buy 3 new ones. Could a rebuild kit fix them maybe? That would save me $30.

Also, what cheap/easy upgrades should I do first? Drill holes and rubber grommets for oil maintenance, prop balance, etc.

Thanks for your time and help! I greatly appreciate it.

 

[MrMediaGuy]

I don't think you can do any sort of damage assessment until you put a fully charged battery into the quad and then check your motors, etc.

If you are not familiar with the pre-flight procedures for Phantom, have your friend put in a good battery, show you how to power it up and calibrate the compass, and then see if:

a) you hear the correct sequence of tones when you plug in the battery. This isn't just a pleasant video-game tune, it's actually sound made by running high-frequency signals through the motor windings. If you hear a note missing, you probably have a bad speed controller (ESC board) or motor

b) you get the proper sequence of blinking lights, which will tell you that the NAZA controller and the GPS module are *probably* working, and finally . . .

c) the motors all start properly. I would start and stop them a few times and observe carefully if they all spin up and down at mostly the same time. A bad or binding motor (since they were in the water this is a particular concern) will be visibly the last to start and the first to stop spinning.

If all those things seem okay, then try to take it off the ground. If you haven't flown one before, you should have your friend show you how.

If any of those steps fail, report back and someone will probably have an opinion on what you should do next.