Hi,

I need some advice or tips ...

I own a P3P and am looking to upgrade to a newer DJI drone (even though I don't really need it now) but I have the possibility to purchase a P4P+ with only 10 flights (what the owner says) for a little more than 60% of its brand new price ...

The owner is selling it because after buying his P4P+, his company purchased one for his professionnal usage and he doesn't use his personal one anymore.

Very tempting but still cautious with nearly 40% discount on the original price ... for a drone purchased early 2017, so normally still under warranty ...

Of course, i check :
- The drone and the RC for any shocks or damage
- I'll turn it one and make a little flight to see if things seem ok

Are there other things that can be checked ?

I was wondering if it was possibile to check the log of his flights of his P4P+ in any way in order to be able to see if there was any strange events or sudden drops in order to point out some issues ...

There is also something that puzzles me. When I look at the P4P+ offer on DJI.com there are two sets of propellers in the box but he says he only got one when he bought it ... I don't recall if I got one or two sets when I bought my P3P ... What comes exactly with the P4P+ ?



Thanks for any advice you can give ....

Cheers ...

Two sets of propellers for sure! (If not, he should have complained with the seller...), then charger, cables etc. You can see it all in "What's in the box"  for the P4P or P4P+

If he only has 1 propeller set, and says it only came with 1 set, he could be trying to cover up a crash that damaged the 1st set of propellers.

Maybe bring a laptop and ask if you can download the flight history from the drone.  I assume these cannot be edited or deleted if it's directly from the device, but I could be mistaken.
If he says there are no crashes or incidents, and the logs show otherwise. I would be in full support for making his lies public on this forum.  

I absolutely cannot stand it when people cover up the damage to their device, especially when it's more than just a couple hundred dollars.

The DAT Files cannot be deleted.
The internal 'black box' - Micro SD card, 6GB on P4P - can contain only that much DAT files.
File writing wraps at 460MB which equals approx. a 20min flight. Afterwards a new file is being recorded.
Plus all the other files (every time the AC is started a file is written) the card is probably full after 10 extended flights.
Then old files will be overwritten...

Analyzing DAT files requires skills. I looked at files and din't understand all these graphs.
The guy is either hiding an incident or it was pre-owned and the previous owner only provided one set of propellers.
I wouldn't trust this "to good to be true" offer.

It's always risky to purchase anything of this nature as 2nd hand item. However, if the owner will tend to cooperate. ask for downloaded DAT files and send them for professional analysis looking for any abnormal inputs. If that's too much of the hassle, at least examine the drone for visible signs of abuse and perform test flight. Any potential problems will be reported on aircraft state page before you fly, check the sensors performance (IMU, compass etc.). Good luck...

Buy it if there's no noticeable damage and fly's like new. You can still purchase DJI Care, you just have to do a verification video of everything functioning as it should. There's your piece of mind.

Thanks for all your feedback ...

I'll have a look at it this morning and check it from top to bottom ...

Other point that was not mentioned ... If he is really the first hand owner, i'll ask him the proof of that (invoice from the DJI shop he said he bought it from)

Shame that it seems that easy to check the logs of the drone, which would really help in the "GO / NO GO" decision ...

Anyway, there is no pressure, still have my P3P .... An opportunity if missed won't be a drama ...

Just contacted the owner ...

- He purchased the P4P+ two months ago
- He still has the original invoice
- He bought it from a DJI official brand store (flagship store of DJI in Shanghai)

Just still puzzled by the one set of propellers instead of two ...

here's a question,

how can one prove if a phantom has even flown? is there some log that will easily show its not been flown?

marctronixx Posted at 2017-4-13 16:53
here's a question,

how can one prove if a phantom has even flown? is there some log that will easily show its not been flown?

That is what I was previously asking in my original post ...

Because you can then control :
- The number of flights
- An any incident during those flights (crash, battery issues, etc)

If he bought it in Shanghai directly, he could have payed much less than what we pay for them here and in that case he might not be losing much if anything selling it for what it is.

I mean, honestly, for 60% or so of brand new price it is a deal.  Look at the logs he provides, see if he will show you ALL the logs he has, and see if he uploaded the logs to DJI and if so, call them with the serial number and see if they can tell you if there is anything wrong with it.

If you can't verify it like that, then you might be better off passing on it.  You would hate to buy it, find that logs were never uploaded, go to buy DJI Care Refresh for it and upon uploading of logs and such find that it was crashed and has issues.  I am not even sure you *CAN* buy DJI Care Refresh for a second-hand P4P+, I thought their terms stated it was only available to the original purchaser.

Honestly, for that much money it might just be better to buy new.

Brian Fist Posted at 2017-4-13 17:19
If he bought it in Shanghai directly, he could have payed much less than what we pay for them here and in that case he might not be losing much if anything selling it for what it is.

I mean, honestly, for 60% or so of brand new price it is a deal.  Look at the logs he provides, see if he will show you ALL the logs he has, and see if he uploaded the logs to DJI and if so, call them with the serial number and see if they can tell you if there is anything wrong with it.

Thanks for your reply ...

I am in Shanghai also myself (as well as him) ... So 60% of the original price is compared to the original price in China ;-)

Indeed for all the other points ...

I am meeting him at lunch time (Time of Beijing, as we say here) and will try to download through a USB cable the logs from the P4P+ ... I understand that it is possible ...

Thanks for the tip calling DJI with the serial number and asking them an assessment ... Not sure though they will just answer like that but i'll give it a try and see if it is possible ...

He might start to think that I am picky but as I said before, I am not in a rush ...

Other thing I might propose to him, since regulations for drones are kind of strict here in China, is to go to the DJI shop in question in order to deal with the change of owner registration directly there and also use this occasion to point out the missing set of propellers ...

Mattcoq Posted at 2017-4-13 17:28
Thanks for your reply ...

I am in Shanghai also myself (as well as him) ... So 60% of the original price is compared to the original price in China ;-)

I thought , and as I got new with mine, that you only get a spare set of 4 blades.

Hi,

Finally I bought the P4P+ mentioned above and checked it how many flights it had ....

6 in total
The battery had only 8 charges
Checked also the flight data with healthy drones and nothing in particular came out from those logs

Here are some photos of my first night and only flights with in this week ...
All were shot at Iso 100 and shutter speed of 2 seconds