Still cannot believe it - crash

Annevanzwol · Apr 7, 2017

Remember reading somewhere that it is not if you will crash your drone but when. Well I found out. It was today. Still cannot believe it as I always try to be aware of my surrounding and any obstacles in it. Also I try to read every crash post to learn from it. Just like so many before me I flew it sideways into a tree

Feel like such an idiot. To make matters worse it fell into a muddy ditch and was partly submerged.

Apart from the props it does not show any mechanical defects. I took it apart to clean it and currently it is drying. Tomorrow I plan to re-assemble it and see if it still flies hoping to avoid going to the refresh program and not knowing if I will receive a monday morning model as replacement. Two questions.

The battery seemed to be fine. All four leds were still on. However after brushing the mud from the contacts under the tap (in off mode and only short after which I shook off the water) it seems to be dead now. Is there a way to reset it of check the battery health?
Some of the flat cables connectors had some type of glue on them. I assume to prevent them from vibrating loose. Should I apply some hobby glue when re-assembling?

Would appreciate your feedback. Below some pictures.

hychewright · Apr 7, 2017

Sorry to hear about your crash. It does not look too bad, with luck maybe all you will need to replace is the Props. Some pilots submerge their Mavic in rice to collect all moisture. Good luck.

Former Member · Apr 7, 2017

The battery might have shorted out. I have done a bunch of repairs on submerged drones, and the battery has rarely survived. You can try charging it again, maybe that will help.

Spin all the motors with your hand and feel for any gritty resistance. You have one set of black props that were broken to the hub, that motor might have gotten damaged.

Turn the FS ESC board fan by hand and see if it spins freely. Looks like some mud might have gotten in there.

You should probably use some type of glue to hold those connectors down again. It will need to be heat resistant because the inside of the Mavic gets really hot.

Im fixing a submerged one for a customer now. When we put a new battery in it all it gave us was a death beep which usually means esc problem. He will need a new FS ESC board, Core board and battery. The camera and gimbal survived and work fine.

Annevanzwol · Apr 7, 2017

Thunder-drones said:
The battery might have shorted out. I have done a bunch of repairs on submerged drones, and the battery has rarely survived. You can try charging it again, maybe that will help.

Spin all the motors with your hand and feel for any gritty resistance. You have one set of black props that were broken to the hub, that motor might have gotten damaged.

Turn the FS ESC board fan by hand and see if it spins freely. Looks like some mud might have gotten in there.

You should probably use some type of glue to hold those connectors down again. It will need to be heat resistant because the inside of the Mavic gets really hot.

Im fixing a submerged one for a customer now. When we put a new battery in it all it gave us was a death beep which usually means esc problem. He will need a new FS ESC board, Core board and battery. The camera and gimbal survived and work fine.

Thank you for your reply.

Former Member · Apr 7, 2017

Youre welcome and good luck. Let the board know how it comes out.

Former Member · Apr 7, 2017

BTW, I have sent in and received back many Mavs to DJI and aside from it taking an eternity to fix, the refurbs they sent me always come back in as-new condition. Others might have different stories, but DJI does a good job at repairing, or replacing them. If your battery is toast, it will cost at least $79 to replace it (thats what I sell them for), and that money will buy you a refresh. That would be the path I would choose.

alexcannas · Apr 7, 2017

Don't use water to clean it. Allow it to dry and then use some alcohol. Ideally do not spray it directly, but on a brush or towel.

Annevanzwol · Apr 7, 2017

Thunder-drones said:
You should probably use some type of glue to hold those connectors down again. It will need to be heat resistant because the inside of the Mavic gets really hot.

Do you know by any chance how hot? I have a glue pistol (probably operating at 110 oC). Do you think the inside of the Mavic will become higher than 110 oC?

AdventureCity · Apr 7, 2017

Annevanzwol said:
Do you know by any chance how hot? I have a glue pistol (probably operating at 110 oC). Do you think the inside of the Mavic will become higher than 110 oC?

I think this is why he mentioned that it should be heat resistant. The glue pistol uses heat; the glue has no melting point but gets softer and softer the warmer it gets. I suggest RTV silicone glue/caulk which can be cut with a knife if you need to separate them later. This is the black stuff I found on my connectors when I opened mine up.

AdventureCity · Apr 7, 2017

Annevanzwol said:
Thank you for your reply.

Just a thought on the battery: you best action might be to put it in a bag of dry rice for 3 days or so, before trying charging. If there is a chance of battery survival, this should remove moisture that can cause shorting when you charge. Hopefully even that can be saved.

Annevanzwol · Apr 7, 2017

AdventureCity said:
I think this is why he mentioned that it should be heat resistant. The glue pistol uses heat; the glue has no melting point but gets softer and softer the warmer it gets. I suggest RTV silicone glue/caulk which can be cut with a knife if you need to separate them later. This is the black stuff I found on my connectors when I opened mine up.

Ok. Thx. will look into some high temp silicon glue.

cobra46 · Apr 7, 2017

Most electronics don't like to get above about 60 C. If your glue stays solid until 110 C you should be good.

Annevanzwol · Apr 8, 2017

Hi all. Re-assembled my Mavic and did some testing. Normal flight, tripod mode, RTH, active track etc. Apart from one gimble overload error message (landed it immediately and moved in all directions with hand after which the message did not return) and some fog in the lens (hope it will dry out next couple of days) it seemed fine. Want to see how it holds up in the coming weeks. Battery is still dead. When plugged into the charger the charger hub gives a red light.

Did get some 'strange' obstacle avoidance warnings high up in the air. Turned out I was being stalked by a bunch of oystercatchers. LOL. Followed me up and down and two even chased the Mavic almost all the way to ground level. Thanks for testing the obstacle avoidance.