200FT full power off crash = GPS inactive = Help :(

[ediprospero]

I have been doing some research on other forums and cant seem to find an answer so I figured I would ask fellow P2er's.

A little backstory: was flying with a friend and the neighbors spotted us. The neighbor's 5 year old son became ENTHRALLED with my Phantom. I told him I would charge it up and let him "fly" (his dad is also a nice guy and really appreciated it). I brought it back outside and put it up to about 200 feet and let him put his hands on the controls while I held on. I was very careful to keep an eye on what he was doing. I let him move the sticks a little bit by himself but kept my hands on the remote (what he was doing was very similar to "button mashing"). I looked up to locate the drone, looked down and back up. Somehow, someway, in that time, from 200 feet, he put the sticks in a power off position and the drone fell from the sky.

It looked much, MUCH worse than the end result. All 4 props snapped, the casing on the Zenmuse H3-3D cracked and it had some dirt on it. I bought new props and a new Zenmuse but here is the issue....


THE ISSUE AND WHAT I HAVE TRIED:
When I full powerup in GPS mode, the lights flash yellow and in the air the drone wont maintain its location. Again, remote IS in GPS mode. I get the constant yellow flash which also indicates the drone is not in GPS. Again, double check everything that seems it would be in GPS mode (it all is set to GPS), yet I still get the yellow flash. Checked to make sure the GPS is still attached inside, it is. Ran re-calibrations inside the Assistant also and same issue.

Any ideas? Could I have damaged something internally?

Thanks,
Eric

 

[MrC]

If you are sure the cable inside is attached ok then you could have broken the gps. They are ceramic and break easily. Have a close look at it. Peel off the shield over it and have a look.

 

[ediprospero]

Thanks. Are there any signs I should look for, or just a crack? Also, how hard are these to replace?

 

[terrylowe]

Thanks. Are there any signs I should look for, or just a crack? Also, how hard are these to replace?

Very easy to replace and relatively inexpensive. Many people are "upgrading" with a thicker version and connecting with satellites indoors.

 

[TeamYankee]

This happened to me a while back... but I just had the red flashing lights as it was trying to receive the GPS sats... I had broke the GPS ceramic antenna (obviously cracked).

You are getting the yellow lights.. this may indicate the GPS module itself is broken - have you connected the Phantom back to the PC for a full IMU calibration and diagnostics?

 

[ediprospero]

I believe I did all of calibrations possible including the advanced IMU, GPS (x, y, z) and looking for errors. I will let you know shortly what the GPS module looks like.

 

[ediprospero]

It looks like to me that the GPS module is intact. Uploaded pic for second sets of eyes.

 

[FedeVision]

Hi, ceramic part is on the other side, GL.

 

[ediprospero]

VOILA! Looks like I need to do some shopping. Uploading cracked GPS ceramic for knowledge base.

 

[aartsf]

Elsewhere on this forum there is a threat where somebody is offering new (and better/thicker) GPS-ceramic units quite cheaply. You find the threat under the topic "classified" of this forum.

 

[kirk2579]

ABSOLUTELY take this time to update to the 4mm antenna
Only good things can happen like real fast sat lock, higher sat count and just plain comfort knowing sat lock is NOT going to be an issue
digikey has for about 5 dollars 931-1015-ND or 931-1126-ND 4mm 5 db gain

 

[ediprospero]

Thanks for the suggestion. Funny you say that because I just order a 5 pack off of eBay for 9.99. Better than replacing the entire GPS unit at 165+. Hopefully the new installation goes well and I'll be on my way. Thank you guys.

 

[jonstatt]

I feel for you and I hope you get your drone sorted. I know you were trying to be generous and kind offering the kid to play with your drone. But I think this is a lesson for everyone that reminds us why the drone carries an 18+ age rating on it. You cannot keep your eye on a kid every second and the drone could do serious damage to someone or something, apart from damage to itself...... This is certainly a lesson to me to keep tight reigns on who controls mine!!

Good luck with fixing your drone and hope you get many more good flights out of her.

 

[ediprospero]

You are COMPLETELY correct. I thought I had the situation controlled and it goes to show, you can truly never. Lesson learned nonetheless. You can believe I will reigning in on who touches the remote.

 

[shabba007]

I think there should be something built into the software that prevents the 'switch off' from happening when its at altitude. Would have thought that would be easy to add.

 

[TeamYankee]

I think there should be something built into the software that prevents the 'switch off' from happening when its at altitude. Would have thought that would be easy to add.

It's there as an emergency shutoff... no matter if it's flying or not. It amazes me why some people have a "fly away" and watch the quad fly off into the distance and never activate CSC as a last resort when fail safe fails!

 

[MrC]

It's quite tricky to replace the ceramic gps bit. Soldering required. I think there are some guides how to. Or depending where you are there is a guy on here selling it already installed. You send him your whole gps unit and he sends it back with the new 4mm one fitted.
Good luck and if you do it yourself maybe document it.

Here is a handy youtube vid of it -
[youtube]https://www.youtube.com/watch?v=Y5EI-MzyoAI[/youtube]

 

[ediprospero]

So quick update... Get ready... Here comes the info overload.

New 4mm GPS antennas arrived. Quite the chore installing them. The above video was helpful but there was a bit of "freelancing" I had to do to get the old one (2mm) out.

Recalibrated (basic and advanced) inside the software. Turned the Phantom 2 on on my back deck where it has generally always logged satellites. Still flashing yellow. Tried a couple of quick tweaks to make sure everything was OK, and turned it back on. Set the home point, STILL yellow. Opened it back up, checked the solder, made a correction (not sure if it was needed or not) and put the Phantom back together.

This time launced in an open space. Phantom fired up, still flashing yellow, set the home point, still yellow. It gets about 5 feet in the air, and then all of the sudden rapid green flashes and I get the slow green flash to indicate GPS mode. I landed, powered off, did the same sequence and got the same result. Slow yellow on ground, to rapid green once in the air to slow green to indicate GPS mode.

GREAT!.... right? Not so fast, now when I switch to ATTI, it remains in GPS mode (green flash) and there is no yellow flash. I am hoping this is a simple fix because I have been grounded over 2 weeks now and my fingers are raw from tinkering. I guess its not the worst thing that it now flies in GPS mode only but I am concerned it has not registered its home point. A couple of contributing factors about tonight could be the 5 inches of snow on the ground or the 12 degree weather. Its abnormally cold here.

Anyway, any thoughts here? I thought it was strange but maybe its not. I am concerned it doesnt log GPS mode while on the ground.

 

[TeamYankee]

by TeamYankee » Tue Feb 10, 2015 11:34 am

This happened to me a while back... but I just had the red flashing lights as it was trying to receive the GPS sats... I had broke the GPS ceramic antenna (obviously cracked).

You are getting the yellow lights.. this may indicate the GPS module itself is broken - have you connected the Phantom back to the PC for a full IMU calibration and diagnostics?

A faulty GPS antenna shows up as a flashing red lights... looking for satellites that it will never find.
A faulty GPS unit would look like yellow lights.. ATTI mode as far as I know.

Unplug the GPS unit and power up the P2 - do you get the same flashing light sequence?

The P2 software may indicate that the GPS is "not present" even when it's plugged in.

Also check the GPS plug... it has "issues".

 

[ediprospero]

Went out for another test flight last night and same thing... Flash yellow on the ground, get to about 10-15ft and then I get the rapid green as if it picked up the Satellites. Flashing green from there on out.

Still pretty confused... When I plug in to Assistant, my 3 GPS values are 0, 0, 0. No IMU calibration needs to be done, although I have done it.

If I set the home point while its flashing yellow will it still be able to find its way home in Fail Safe? That's my biggest concern.