FC40 won't connect to GPS after a crash

[rriver1010]

21 flights with success. Then a bad battery dropped my FC40 out of the sky like a falling rock. Classic, I said, "Oh, this isn't going to be good." It bounced, Zenmuse gimbal broke, and otherwise all was good. I have fixed the gimbal, re-connected it and it works fine with my GoPro3. I have checked all external wires and connections and they appear to be re-attached correctly. I prepared to take the FC40 out for a test flight, but I can't get it to connect to the GPS in the sky. With controller on, I plug in battery, and both controller toggles are toggled up - GPS mode. All I get is a constant flashing yellow light. I have turned things on, off, took it to different fields to try to get a different GPS signal, and with no luck. Slow flashing yellow light. When I toggle the right toggle downward, I get a fast multi flash of yellow. But no red, no green...nothing. Can you help me with a little trouble shooting? Could there be a connection that I have missed, or something to check that I'm not seeing? I didn't build this so I'm not sure where the GPS antenna, wiring, or other options are located. Thanks for any help you might be able to assist me with. I'm in the nation of Panama where there are NO PARTS.... so I'm 10 days out in shipping on anything I need to buy. Thought I'd try the forum first before sending this thing up to the USA for troubleshooting. THANKS!

 

[rriver1010]

By the way, the unit will power up, spin up, and will fly out of GPS mode. So motors and connection between controller and drone are good.

 

[kyeikofi]

Have you tried a compass reset? (not calibration)

 

[IflyinWY]

Welcome to the forum rriver1010.

That's funny, you're in Panama and almost everything on this planet passes right through your country, but it takes 10 days for you to get a part.

Too bad you showed up because of a crash. How about posting some video when you have time.

Have you opened the clamshell, separated the top from the bottom and checked connections there?
There are tons of videos which can guide you through the process.
Hope you have a tiny Phillips screwdriver...
squeezing the pieces together (with your fingers) might make it easier to loosen the screws.

I don't know about you, but I really like my FC40. It's one tough bird.

 

[rriver1010]

Thanks for the ideas. I'll try to peel the top off and check it out. And on the other post - I haven't heard of a Compass Reset but I'll get data on it and try that out... much appreciated on helping me to get this bird back up and running.

If interested, here's a shot of a farm that we did last month. Notice the Baru Volcano in the background. https://www.youtube.com/watch?v=TmzrKrIq-j4

Thanks again.

 

[rriver1010]

Sorry to bother you, but I can't find anything anywhere about a COMPASS RESET. Can you give me a link, a hint or how to reset this compass? Thanks.

 

[kyeikofi]

A few links for you. I would do an IMU calibration (1st link) and if that doesn't work degauss your compass (2nd link)

http://wiki.dji.com/en/index.php/Phanto ... alibration
https://www.youtube.com/watch?v=3-3vTmF82mE

 

[J.James]

Check that your ceramic antenna on top of the gps modal is not busted. Its very frazzle and very common to break in a crash esp any crash if it lands on its top side at all.

The gps unit is in the top part of the shell under some gray foam shielding tape. Tho to be able to see the top part were the square ceramic antenna is on the gps unit you will have to take out the 4 tiny screws that hold the gps unit in to the top of the shell. If the antenna is busted you will either have to get an entire new gps unit. which is about $160US OR if you are handly with a soldering iron there is a way to just fix the broken ceramic antenna by replacing it with a new and even better one. The replacement gps antennas are about $5US plus shipping. Also the replacement ones usually are thicker and are 4dbi compared to the stock antennas 2bdi So the newer ones actully pick up gps signal much better as well as faster lock on the gps satellites . With my phantoms that have the updated replacement gps antennas in them and some extra copper sheilding I can now get a full 7 gps lock even when in side my house. before It was rare to even get 1 or 2 satellites while inside.

 

[greginjoplinmo]

I have the same problem. FC40 got lodged in a tree. Fell 60 feet landing upside down on driveway. I saw that James J. posted about buying a replacement GPS ceramic antenna for much cheaper than whole unit. I took my phantom apart......and the only thing broken IS the ceramic antenna. It connects to NAZA just fine, but puts all zeros in GPS area. Does anyone know where I go to buy one of the ceramic antennas. I'd like to get in touch with James j but don't know how.

 

[IflyinWY]

I have the same problem. FC40 got lodged in a tree. Fell 60 feet landing upside down on driveway. I saw that James J. posted about buying a replacement GPS ceramic antenna for much cheaper than whole unit. I took my phantom apart......and the only thing broken IS the ceramic antenna. It connects to NAZA just fine, but puts all zeros in GPS area. Does anyone know where I go to buy one of the ceramic antennas. I'd like to get in touch with James j but don't know how.

I PM'd him for you.
I think it's J.James.


wELCOMe To ThE pARtY greginjoplinmo

Where the heck is Joplinmo?

 

[Woody]

http://www.djiphantomforum.net/viewtopic.php?f=11&t=46

 

[J.James]

You can get the replacement ceramic antennas on ebay and also digikey but the sellers on ebay are all less expensive with the shipping. So its the best bet.

If you want to go real cheap but wait forever to get it here is one from thats $3 and change $ with free shipping.
[url=http://www.ebay.com/itm/25-25...w.ebay.com/itm/25-25-4-Ceramic ... 4190499cf5[/url]

or 2 for about $4
http://www.ebay.com/itm/2pcs-Cerami...441?pt=LH_DefaultDomain_0&hash=item2a49d19161

But if you need it quick here is a us seller that sells then in lots of 5 for $9.99 free shipping.
http://www.ebay.com/itm/NEW-Lot-of-...82?pt=LH_DefaultDomain_0&hash=item3a8ebf1eba

These also are the ones that are 4mm thick and are 4dbi ware as the original ones are 2mm thick and 2dbi

The 4mm ones are an upgrade and will give you a much faster gps lock and also can get you a higher gps count even inside a building in a lot of cases. Tho I have noticed to get the to fit in the shell right due to the extra 2mm thickness you will need to either use longer screws and some sort of 2mm plastic washers or spacers on the screw. or the other way thats much easier Is to just use a pair of pliers to peel off some of the plastic fins on the top of the shell were the gps sits and it will give you enough clearance to sit flush.

and here is a video I found recently were some one shows how to replace the antenna if you can solder. (if not there is a person or 2 in the classifieds that you can send your gps unit to and they will replace it for you)

https://www.youtube.com/watch?v=Y5EI-MzyoAI

 

[greginjoplinmo]

Thanks. I appreciate it. I bought a ceramic antenna from mouser electronics for about 5 bucks and then some more aluminum foam to cover it back with. All the motors work. Lights work. Connects to NAZA no problem, just zero GPS values and James was right. The ceramic antenna was cracked but circuit board itself looks solid. I guess I'll see if that's the problem. If anyone has any other advice or ideas I amMOREthan willing to listen to someone wiser than myself. [email protected]

 

[J.James]

im going to almost bet money it was a broken gps being them thin 2mm ones almost always break in any crash were it lands on the top and esp if there is any added stuff to add weight like a gimbal or extra large battery which causes them to hit even harder when they do a swan dive. My FC40 I have been lucky with being I tend to fly light and even some bad crashes the gps survived. But on my p2s which are heaver even small crashes always means I had better bust out some more money for a new gps. So im glad I have discovered I dont have to keep shelling out an entire 160 each time I ever have even a minor crash.

Tho now that I have had the thicker antennas in any of the others I have not had any crashes to see if they hold up better then the waffer thin stock ones. But I have a feeling they very well may hold up in a crash better because if I even try to break on of the 4mm thick ones with by hands I cant were as the 2mm thin ones I can snap with my hands pretty easy.

Now I dont even screw around and any others That I have built or had the shell open the very first thing I do is to replace the stock Gps antenna with one of the thicker ones. and also add more sheilding as well as tighten the pins on the plug to the gps because lose pins are also a known issue with the gps units and can cause lose of gps while flying. The gps is one thing I want to always make sure is working the best it can be and the fixes are just to easy to not take the effort to upgrade BEFORE I have any problems related to the gps.

 

[rriver1010]

Get your ceramic here: http://www.ebay.com/itm/25-25-4-Ceramic ... 4190499cf5 or here: http://www.ebay.com/itm/2pcs-Ceramic-GP ... 2a49d19161

 

[rriver1010]

Thanks for all your help. I just got back from traveling and am digging into this. because I live in Panama, i'm going to try to order all potential parts that might be needed, without breaking the bank.

Thanks Kikofi - I am checking recalibrations tonight when I get home. If that doesn't work, I am planning to order a new compass and a new ceramic antenna just in case. I am attaching pictures of all areas we're looking at, and I would appreciate anyone's help in seeing anything I'm not seeing. The compass bothers me - because it looks like, at micro level, that a prong may be broken off of the compass connector. Don't know if it's all connecting together correctly. Can you see anything and would this compass disconnect be the entire reason that the unit will not connect to the GPS... just flashing red? Thanks for looking at pictures and sending any ideas, response ect. Planning to order new compass and cable, and GPS ceramic antenna, and some additional shielding. I am totally open to suggestions, and even upgrade ideas while I have this monster taken apart. I JUST WANT TO FLY!!!!

Daniel
PS See attached photos...

 

[J.James]

from that last pic it looks like you still have all the pins on that plug and the good thing is the solder pads on that board all look intact. If you can solder or know some one that has an iron and can solder you would just need to straiten the pins out put some flux on them and resolder them back in place.

 

[J.James]

I bought a ceramic antenna from mouser electronics for about 5 bucks and then some more aluminum foam

Were did you acquire the aluminum foam stuff????????? I have been looking and looking for the foam covered copper shielding like dji uses and the closest stuff I was able to find was freaking $500us for a big roll of it and thats just a bit more lol then I might ever need.