Question about GPS antenna connector as "safety switch"

[Monkeyleg]

The GPS antenna must be plugged in and the GPS antenna must be working for the Phantom to power up. If the GPS antenna connector were to become disconnected with the motors running, would the Phantom power off, or does it stay powered on even if the GPS antenna is somehow disconnected?

I had my P2V+ just fall out of the sky today. I was fortunate in that it fell from over 60 feet, but hit front down in some very soft mud. There's not any visible damage. It flipped over into a shallow puddle of water, though, so I have to let it dry out for a day or two.

When I removed the top shell, it seemed like the GPS antenna connector was already disconnected. I don't see how this could happen, but I'm wondering if it did disconnect, could that be the cause of the fall?

If a disconnected GPS doesn't power off the Phantom, then I must have had an ESC go bad. There's no signs of any problems inside the bird.

 

[Mako79]

There is only 1 way to test.
Pull the cover off and leave the GPS plugged. Start motors with no props on. Pull the GPS plug off and see if the motors stop.

 

[Monkeyleg]

Yeah, there's that way. I don't want to power it up for a day or two until I'm certain that all of the moisture is out of it. If it doesn't start, I won't know if it's the GPS antenna or something else.

Meanwhile, I'm just trying to consider the possible reasons for the crash. It obviously lost power, and I don't know how many ways there are to have that happen.

 

[Monkeyleg]

The answer to the question is, yes, the motors will continue to run if the GPS antenna is disconnected. I had to wait until today when everything was dry to test it.

It had to be an ESC that quit. Just to be safe I'm replacing all four, even though two work.

I got off cheap. A crash from 60 feet and just two ESC's fried.

 

[Mark The Droner]

Can you tell us about your battery? What was the percentage when you launched, and when was the last time you used it? Thanks

 

[Monkeyleg]

All 5 of my batteries have 93% or more of their useful life left. The battery would have been charged to 97% to 99% when I took off. By the time the Phantom got back to within a few hundred feet of me, the charge was still 30-40%.

 

[Mark The Droner]

When was the last time you used it?

 

[Monkeyleg]

I had the crash flying on Sunday. I had the Phantom out in the same field on Saturday for about an hour and a half, and was out a week or so before that in a different field.

There's a large tree in the field, but I'm very certain I didn't hit it. The Phantom appeared to be well north of it, and in the video feed on my tablet, it was well above it.

There's a big chuck of propellor missing. I wish I'd taken the time to search for it, as that might have given a clue as to what happened. If I'd been recording, that would have told a lot more.

 

[Mark The Droner]

lol

I'm trying to find out when was the last time you used the battery.

 

[Monkeyleg]

I used it today to test the Phantom, and everything is fine with it. I obviously used it yesterday when I crashed. And I used it on Saturday, as well as last week. I almost always go through all my batteries when I go out to fly.

 

[Mark The Droner]

Okay, you used the battery Saturday, Sunday, and Monday and Sunday was the day it crashed. I was thinking it might be an auto-discharge issue but it seems unlikely. On the other hand, if you used the battery on Saturday, you obviously charged the battery, so wouldn't it have a 100% charge on Sunday when you launched again?

Anyway, there seems to be a lot of crafts falling from the sky apparently because pilots are flying with a battery that has started auto-discharge - and then they're not recharging the battery because they think it's "good enough." There seems to be some kind of firmware bug that allows the battery to shut down in these cases. But that doesn't seem to be the problem in your case.

Good luck.

 

[Monkeyleg]

Great. Another new design "feature" to worry about. I'm very certain the last crash was due to one of the thin wires on the 2312 motor breaking at the solder joint on the ESC. Then there's the ESC's themselves to worry about. Now it's batteries.

There's still 35% of charge left on the crashed battery, and no sign of problems. It's not damaged at all. Thank God for mud.