Phantom 1 goes into failsafe at around 20m

Redhammer · Jul 7, 2014

Hello, I have recently started flying a phantom 1. I don't fly very far because I'm still learning the controls and whatnot. Upon testing recently the phantom acted as if it lost signal at around 20m, failsafe kicked in and in landed back at its starting point. Did a second flight with same result. I have noticed from watching videos of other phantoms that my phantoms start up sequence might not be completing. Mines does as follows. Self test completes and records homepoint (I assuming because failsafe landing worked fine) it doesn't seem to search for GPS Sats after that. There is no green or red flashing indicating it has found sats and no yellow flashing lights indicating it is warming up. After the start up sequence and recording homepoint (this takes about 5 sec) there are no lights. I've waited a few minutes before but after the initial start up test motors will turn on. Upon reading the manual and watching some start up videos I see phantoms flash a green light during flight but I don't see that either.
Any thoughts on what is going on?

Earlier flight tests were on the 3.16 firmware and I'm quite sure I had it out 40-60m and everything seemed fine. The issue described above is on firmware 4.02. I have updated to the 4.02 firmware, calibrate compass, IMU, and transmitter. This phantom was damaged (not by me

) and I was tasked with fixing it. I have replaced one motor ESC board and had to solder on a wire or two that came off the main board.

OI Photography · Jul 7, 2014

Can you do a quick vid of the LED sequences you do see at startup and before it goes dark on you?

Also, are you sure the flight mode switch isn't in Manual mode?

Redhammer · Jul 7, 2014

Sure I'll have you a video up in the next hour. Switch 1 and 2 are both in full up position during start up.

Redhammer · Jul 8, 2014

I took this video in a different area and I got a little more led activity. Right when the video ended it stopped blinking and I put the battery pack in and started the motors. http://youtu.be/jjb0uOj24no
I'll check my transmitter in the Assistant to make sure the S1 and S2 switchs are working correctly.

OI Photography · Jul 8, 2014

It's hard for me to tell in that vid if it's flashing green and multiple reds or multiple yellows. I've never seen green + yellow, it should be green + red, and that's the proper behavior while it's still locking satellites. Normally you need to wait a couple of minutes for it to get enough satellites to go to just green blinking.

Redhammer · Jul 8, 2014

It is indeed yellow, I've got a new LED board and Receiver board coming. Debating on downgrading the firmware to check and see if that will make a difference.

J.James · Jul 9, 2014

If its flashing green and yellows thats usually meaning its in atti mode.. Check that your s1 and s2 switchs are working right by hooking the phantom in the the naza software and toggle the switchs and make sure they are showing the right modes for each position and also try to put them in all 3 of there positions and wiggle them to make sure you dont. see the modes jumping around if the switch is breaking connection.

If the switchs are going bad they could be breaking connecting and some how putting it in to atti mode with is the default if there is a broken connection on the s2 switch and when its flying it could be going in to fail safe if the switch is shoring out or even if there is a wire off the back of it and its touching the center post on the s1 switch.

Redhammer · Jul 9, 2014

It does make sense that it isn't in the correct mode. I can't find any info on a LED code of Green, Yellow, Yellow. Although I believe if your in manual and motors are started you will get no flashing LED during flight as I do. I'll take apart the controller and check the switch physically.

J.James · Jul 9, 2014

I'll take apart the controller and check the switch physically.

Its actually easier to check it threw the naza first rather then checking it physically being the only way to physically check it is with a multi meter. And it can be a pain in the butt to try and hold the probs on the switch while also jiggling the switch in all the positions to see if its breaking contact.

J.James · Jul 9, 2014

DJI Introducing the LED Indicator of Phantom video. According to this video I think its saying there is either a stick not centered error or its saying there is an internal sensor error.

https://www.youtube.com/watch?v=AVUsfMIjcY8

Redhammer · Jul 18, 2014

Ok back with an update. I have replaced the LED board, the 2.4ghz internal wireless receiver, and the compass. Full re-calibration of everything and I think that has sorted it all out. Start up LED's look normal, searching for sats now proceeds as it should.

One last tiny mystery I'm unclear on. While flying the phantom blinks one green as I've seen all other phantoms do. The farther away I move it will blink one green, one yellow and even further away one green, one red. Is this representing signal strength?, losing sats maybe?, or is this abnormal altogether?

J.James · Jul 18, 2014

That sounds like its losing the gps sat connection if its blinking a red.
but that should not be putting it in to fail safe. Inless there is some thing wrong with your s1 switch or your transmitter is only sending a very weak signal. Tho being its having 2 problems at once going on that makes me think its the swtich is bad and puting it in to atti mode and fail safe on its own.