Used drone no history = headache !

[Perceval]

Hi all,

I've just joined the forum after reading countless pages on different topics. I have bought a used Mavic pro with no history, factory battery and charger, RC seems working ok. It's my first drone. The sticker on the top of the case with the serial number, ssid codes etc was removed so I have no info on it.

Problem?
The drone starts, red LED on legs, each motors moves a little on startup. The status light is off, it's not possible to link to the RC or use the WiFi. The link Led is not blinking either.

Was unit in a crash? Possible, there are traces marks all over the drone.

What have you tried so far?
Upon opening, I found both WiFi board coax cables disconnected (cut or ripped off). I disconnected the WiFi flex cable and removed the WiFi unit, as I understood I can use the RC only for now.
The white coax from the front antenna was also disconnected/cut. I am not sure how to repair the cable, soldering did not work. I can find no spares antenna online, only complete arms. I don't know if there are some cheap antenna which could work good enough for me to assess the drone condition before I spend more money.
The flex cable running between the 2 main PCB was ripped off as well. I guess this is why the drone status light is off, it's not recognised by the computer etc. I've ordered a spare flex cable and hope to then be able to link it to the computer, see a status light and start from there.
One of the 2 small landing cameras on the PCB as a damaged flex cable (they are cameras, right?) I've not found spares online, do you maybe have a link? I guess it won't fly without it being repaired?

What device are you using ( iphone , ipad, Samsung , etc)? iPhone, android, windows 10 laptop

What firmware are you running ( aircraft, remote controller)?
Aircraft unknown
RC not sure how to check

What Go app version are you using? 4

Any modification? (if so what)

Did you change anything or install any apps? (if so what)

Do you have a video or pictures of the problem? (if so post link)

Thanks a lot for the help you can bring!

 

[MAvic_South_Oz]

Sounds like it needs professional attention to be honest.
I'm not sure of drone repair companies in the UK, maybe put a post up in the UK section asking for peoples recommendations in your country, hopefully you might get some personal experience in the replies.

A search here for > UK drone repair < brings up a few to read through . . .

Search results for query: UK drone repair

Good luck, the M1P is a decent drone, still flying mine since 2017.

 

[Perceval]

Thanks for the reply. I would prefer to repair it myself for the satisfaction of diy but I would turn to a pro if really needed. I had a look at your suggestion and found some useful comments about the companies (or lack of) in the UK, so thanks for that!

 

[howardK]

I have 2 of the M1P's and love them. For repairs i have used Thunder Drones (Thunder Drones – Specializing In Dji Drones) and they are excellent. They are in the USA so i am not sure of the logistics for cross pond repairs.

 

[offtheback]

I have 2 of the M1P's and love them. For repairs i have used Thunder Drones (Thunder Drones – Specializing In Dji Drones) and they are excellent. They are in the USA so i am not sure of the logistics for cross pond repairs.

+1 on Thunderdrones for expert repairs and fair pricing.

 

[Capt KO]

You bought a mess. Somebody’s been removing cables or cutting them for a reason. Probably better off buying a crashed drone and start swapping parts as the ones you’re end up buying will cost more than a working drone. Parts are available here in the US or AliExpress from China.

 

[MAvic_South_Oz]

I would prefer to repair it myself for the satisfaction of diy but I would turn to a pro if really needed.

The only thing that concerns me is the possible complexity of a DIY repair process.

You bought a mess.

The problems description means it could be a long drawn out process of trial and elimination, and possibly getting very costly in both £ and time replacing bits and pieces / waiting for parts etc.

DJI or other experienced repairers can swap out and get through a repair fairly efficiently.

Good luck either way, DIY can be very satisfying, but usually best reserved for simple obvious one issue problems.

 

[Perceval]

Thanks all for your inputs and suggestions, I think it's time for me to post an update!
I've received today and fitted the new flex cable between the 2 main PCBs, and as I expected it got me into the drone (I'm happy). I got the rear light status on, it connected first time to the RC, accepted the sd card and I could access the AC in the dji go 4 app.
I had all forward and downward vision sensor error messages. They almost all got away after I check the flex cables connections, and I am left with the downward left sensor issue which I knew about since its physically damaged.
It's mostly raining today so I gave it a quick go outside, compass didn't need calibration, gimbal calibrated fully with no issues. I used the auto take off, tried the controls a little bit and auto landing. It was my first ever flight and I want to be in a large and clear area before I really start flying it.
I might just be lucky be I'm optimistic, I'll change the downward vision sensor, even if it seems fine without. I'll check that I get a clear video recording on the sd card. And finally I will need to change the antenna in the front right arm but it seems that it can wait a bit for now, it might be OK as is as long as I don't fly too far...

 

[Clintoops]

Thanks all for your inputs and suggestions, I think it's time for me to post an update!
I've received today and fitted the new flex cable between the 2 main PCBs, and as I expected it got me into the drone (I'm happy). I got the rear light status on, it connected first time to the RC, accepted the sd card and I could access the AC in the dji go 4 app.
I had all forward and downward vision sensor error messages. They almost all got away after I check the flex cables connections, and I am left with the downward left sensor issue which I knew about since its physically damaged.
It's mostly raining today so I gave it a quick go outside, compass didn't need calibration, gimbal calibrated fully with no issues. I used the auto take off, tried the controls a little bit and auto landing. It was my first ever flight and I want to be in a large and clear area before I really start flying it.
I might just be lucky be I'm optimistic, I'll change the downward vision sensor, even if it seems fine without. I'll check that I get a clear video recording on the sd card. And finally I will need to change the antenna in the front right arm but it seems that it can wait a bit for now, it might be OK as is as long as I don't fly too far...

That's great. That you got it in the air. Enjoy flying

 

[CaptainMavic]

I bought a MM and a MP sold “as is, for parts, won’t fly”. Got good prices on both. I knew nothing about drones but I can fix just about anything. I did a lot of research on the problems that they both had and made the repairs. Both now look and fly like new. Guess I got lucky. These forums, and the internet were full of answers. You can get a lot of parts from eBay, Amazon, and this forum’s classified ads section. I remember when there was no internet and the only information was from books or from someone who had the knowledge. Hopefully you got your MP for a really low price. There is a certain amount of satisfaction in doing the work yourself. Stick with it and ask a lot of questions, chances are that you will fully bring your drone back to life!