APM 2.6 Cut all 4 motors & fell out of the sky .... !!!

[darlofranco]

I have 450 quad with APM 2.6 FC board and while flying today all 4 motors stopped 

I was in loiter mode hovering about 30ft high with good sat lock and plenty of battery left when crash bang wollop... luckily only broke the landing gear. I checked it with the same battery when I got home and hovered in the back garden for a good 5 mins without any problem.

I can';t trust this now without knowing what could be the fault and how to fix it.

Any ideas guys?

Thanks!

[hoverfly]

Try down loading the logs in Mission planner  and do an auto analysis. I would also check the failsafe settings and the throttle cut switch on your t/x .

[shawdreamer]

knowing the rest of your setup might help.

for example, how are you powering you entire Apm?, are you using the jumper and powering both sides from a a one of the escs or using a APM aproved power module? if using the esc and jumper option the APM 2.6 is susceptible to brownouts when using some of the less expensive escs and these brownouts can happen at anytime and any battery level even when the frame is simply loitering.

[darlofranco]

Thanks for the suggestions - I';m using an APM power module, I';ll check the logs and see if I can make head or tail of them tomorrow.

Might have to come back and ask for advice on hoe to read the logs ... 

[shawdreamer]

you might want to check all the obvious things too.

seen as you lost power to all motors simultaneously you can rule out a singular esc or motor failure and and focus more on signal transmission and main power distribution.

check  all your connections and solder joints on your pdb, focus on the main power in as a failed joint on the outbound side would have only effected one esc/motor.

check the connection of your power module into the APM, Ive seen the female connectors inside the the plug pushed out when their plugged in before (especially on the cheap clone versions) and it gives you intermittent power failure, best way to make sure is unplug from APM and power module and give each wire a careful pull to check for slippage.

check your signal wires both on RX and APM side as the APMs default failsafe for signal loss is to cut motor power (unless instructed otherwise beforehand)

failing the obvious stuff the APM log will be the only chance of picking up something less obvious.

[darlofranco]

Thanks guys, found it! Slightly loose 5v wire coming out of the power module plug. I don';t think it came loose in the crash as I had the module zip tied to the frame so it couldn';t move. A gentle tug and it came out! 

Crappy plug... can';t get a connection now

[RawLiquid]

Be very careful with that lipo man, an impact from 30ft is more than enough to do internal damage to it. If you don';t already take careful precautions, I would suggest something along the lines of only charging it inside a US army ammo can half filled with sand, and don';t leave the area while it charges. periodically check that it remains cool to the touch while charging, should never even feel warm just from charging.