If you say you have checked it all & everything is correct(that was fast   ), then most probably your boards are toast  
I can only tell you what can be the cause, troubleshooting it properly is your chore.

Esc's are very dirty power source for APM. You should either use power module or a separate bec/ubec for powering APM. Sometimes voltage may drop to less than 4.5v on esc's under high load which may lead to a brownout and crash.
Check that regulator too as Hareesh said, completely forgot that!

yes i felt the same i thought the 3dr people would have done some settings which would not allow clones to be flied juss a thought

How to revert back on old firmware ??

Quote from: radiocraft on December 27, 2014, 02:37:49 PM
How to revert back on old firmware ??

Go to
Mission Planner--Initial setup--Install firmware--Pick Previous Firmware (on the right side at the bottom)--Then either select from the drop down menu or click on appropriate image for your configuration.

okie will try with a old firmware thank u all

hey watch my quad on apm 2.6 with latest firmware it flips right on throttle more than 50% well i have calibrated all stuff and its perfect to fly in order of setup sequence...

The video is private.

sry i didnt see that made it public have a look

Hmm. Which is the best stable version of apm 2.6

Hey dude why are you breaking your had so much? Capture the fought days log post it aurdupilot forums and ask them.. See if they works reply. Make due you attach the logs

Quote from: Hareesh on December 28, 2014, 08:33:53 AM
Hey dude why are you breaking your had so much? Capture the fought days log post it aurdupilot forums and ask them.. See if they works reply. Make due you attach the logs

Sorry to much off auto correct :p screwed Mr. Try to capture the flight data logs. Post it on aurdupilot website ask the Dev's to analyze then and get back to you with a work around

hey i am unable to download the logs in txt format in mission planner it gets into some encoded format

Yes I have recorded some logs without props and will post it soon.

hello guys i have made a quadcopter of the below config:
apm2.6
2200mah 3s wolfpack
xxa 1000kv motors
xxa 30amp esc
flysky 6ch tx rx
f450 frame

well i have recently received my apm 2.6 i have updated it to the latest firmware bt it tends to flip right in takeoff above 40% throttle
i dnt have gps or on board compass ...................

(@admin- sry to repost this if i have done it please delete my earlier thread)

Is motors rotating the right way ?
props are mounted Appropriate directions ?

yes motor 1 and motor 2 clockwise
motor 3 and motor 4 anticlockwise
and props are also proper according to the rotation

Quote from: cyberhack on January 02, 2015, 12:31:57 AM
yes motor 1 and motor 2 clockwise
motor 3 and motor 4 anticlockwise

I don't think that's the right config.

EDIT : I found this image here : http://copter.ardupilot.com/wiki/motor-setup/

Look at the config

ohh yeah sry i have considered the motors wrng side i mean i numbered them wrng yeah the motors are rotation as u said ...........(y)

@akhil i motors rotate the same way posted in the picture bt i suppose i have plugged the esc into apm considering the front left as 1 and front right as 3 and similarly others
i suppose attached them symmetrically would that be a prb? i mean i mistakenly considered motor 3 as motor 1 and connected and tried lol i figured it out after breaking so many props   will give it a try tomorrow and let u knw shitt i didnt even see it before anyways thankxx both of u wil let u knw abt the result motor rotations are correct bt bec plugging is wrng  

that means you swapped 1 and 3 right?
if yes then that should be the problem.

yup so silly of me was thinking it was some serious issue with the apm thanxx

best of luck, and next time setting up a flight controller - refer it's manual first

like the butterfly effect