Safety / Maintenance Tip

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After repairing some 30 - 40 Phantoms there's a pattern I'm seeing. Anytime someone tells me "my Phantom fell out of the sky" or "lost power while in flight", the first question I ask these days - "how many crashes?" Standard response - " I bummped a tree" or "I've had a couple of hard landings".

I'm finding most of the ones I'm seeing as "power loss" is because the solder joints from the factory are coming undone. C'mon folks those are tiny solder joints to a pcb that if you bump them hard enough they pop off. "It didn't come off after the crash and you had a dozen successful flights then it just dies in midair - what's wrong?" I'll tell you what's wrong - vibration finnished the job!

My point is - regardless of how minimal the crash appeared PLEASE open her up and inspect the solder joints. It takes all of 5 mins at tops. Whenever I have one open I always check all the solder connections, then hot glue or liquid solder all the usual suspects. I do this to ALL of my clients/fellow flyers rigs, it's an ounce of prevention.

Keep 'em flyin'

MC
 
Thanks for your insight. I know folks have complained about DJI quality right out of the box, without the added hazards created by strong bumps and vibrations of rough landings. Your suggestion might apply to out of the box inspections before 1st flights too.

Your in sight (inside) is always most helpful.
 
My fc40 had a power wire pull off the board on the 4th of July and fell 850 feet to the ground. and i actually had just inspected the solder joints a few days before when I had the shell open and they looked to be good non cold joints. But after seeing the wire and the blob of solder after it came off it was clear it was not soldered on good cause it came clean off the pad on the board and the pad had no solder stuck to it at all. No it and the other wire are soldered down properly cause I soldered them and soldered them properly. and also glued the wires down so they dont yank on the joints when the battery is connected or disconnected. and I also made sure all the other connections are now done right on all the escs and motor wires to. and did the same on my vision.

and one other thing I discovered a few weeks before that was the shoddy way they connect the x60 plug to the wires is also very sketchy and needed to be fixed. Instead of soldering the end of the wire directly in to the solder cups on the plug. What they do instead is they solder pc of solid wire thats a few millimeters long in the the solder cup so its like a pin sticking out the same diameter as the power wire then they cut the power wire flush and just push the solid wire in to the insulation and then cover it with the shrink wrap. So bacicly the shrink wrap is all that's really holding the wire to the plug. WAY WAY WAY not cool. and glad I noticed some thing was wrong one day after hooking my battery up and getting ready to do a flight and when I started the motors the vibration was enough to cause the connection to break contact and it shut off then when I picked it up to see what the heck was wrong it came back on then right back off again. Then when I went to unplug the battery is when the wire pulled all the way out. and was able to see what was up. had it happened just a tiny bit later then it did. I would of for sure had a crash.

Now I dont trust any of the work done by them to be all good or to take it for granted that it is. esp when its some thing that if it goes wrong its there gain and my lose if it caused me to have to shell out more $ to buy new parts or replace the whole thing after it crashes so hard there would be no way to know it was there fault.
 
EMCSQUAR said:
After repairing some 30 - 40 Phantoms there's a pattern I'm seeing. Anytime someone tells me "my Phantom fell out of the sky" or "lost power while in flight", the first question I ask these days - "how many crashes?" Standard response - " I bummped a tree" or "I've had a couple of hard landings".

I'm finding most of the ones I'm seeing as "power loss" is because the solder joints from the factory are coming undone. C'mon folks those are tiny solder joints to a pcb that if you bump them hard enough they pop off. "It didn't come off after the crash and you had a dozen successful flights then it just dies in midair - what's wrong?" I'll tell you what's wrong - vibration finnished the job!

My point is - regardless of how minimal the crash appeared PLEASE open her up and inspect the solder joints. It takes all of 5 mins at tops. Whenever I have one open I always check all the solder connections, then hot glue or liquid solder all the usual suspects. I do this to ALL of my clients/fellow flyers rigs, it's an ounce of prevention.

Keep 'em flyin'

MC
Next time you have one apart could you get a picture & point out the problem areas that give the most problems etc, I'm a nuts & bolts type of guy, pcb's I'm not familiar with yet, will learn.
 
Guipago said:
Next time you have one apart could you get a picture & point out the problem areas that give the most problems etc, I'm a nuts & bolts type of guy, pcb's I'm not familiar with yet, will learn.

1. The points the battery leads connect to the board
2. The points the ESC's power leads connect to the board
3. The points the 3 wires from each motor connect to the ESC

Basically anywhere you see one of those tidy round blobs of solder. They've been common failure points since the P1, I didn't know if they still were but it seems so. It often seems to happen just like described above...the whole blob separates from the pad with no sign it was ever there in the first place. I've long since re-done all those points in mine, and haven't had any issues with them yet.
 
An indication of the visuals
 
I had mine apart to install the flytrex and noticed the live wire from the battery was frayed and I had to put some heat shrink tubing on it. To do so I de-soldered the orginal connection and noticed how loose the negative wire was so fixed that too.

As you say it takes 5 mins to do so it seems silly not to.
 
Here is pic of connections I see most commonly come loose.
 

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I have not experienced any solder failures yet but the points EMC2 highlight make sense ot me.

DJI has used stiff coaxial type wire for this [why???] and it only makes sense that when flexing of the arm occurs the rigid VCC supply lines are apt to shear off the pads.

I have removed many of the wire ties in this area as well so as not to contribute forces.
 
Not a problem. If I can prevent a mid air failure - "It's one for the good guys"
 

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