Hi
I have a P2 which works fine but after I updated to V3.8 the engine doesn't work. i calibrated the RC and the drone. is there any way to fix it?

You're referring to your Phantom 2 Assistant software v 3.8 which is usually installed on a desktop or laptop.  It wouldn't have anything to do with the operation of your P2 unless you used the software to make some kind of catastrophic change to your P2.  

It appears you are in NAZA mode.  That's fine.  

The lamps indicate the drone is linked correctly to the controller and is receiving the signal from the transmitter.  You claim you calibrated the controller.  The compass calibration should be done outside away from ferrous metals.  

Usually when the motors don't start, it's because either the GPS module or antenna is disconnected or not working correctly, or the compass is disconnected or not working correctly.  It's not necessary to be outside or have satellites to start the motors.  But the compass - and the GPS module should be working correctly even if it senses zero satellites (e.g. inside).  

It's not a good idea to have the controller an inch away from the drone.  You should have more distance between them, such as ten feet.  Antenna should be vertical.  When you move the drone away, be careful not to set your drone down near ferrous metal.  

I researched more on youtube.com and found that many people face the same problem but still can't fix the error.
I calibrated the controller via the RC sytem software on the computer and everything is fine.
Calibrate P2 via PT2 V3.8 + RC software (re-calibrate).
I'm not sure what I'm missing.

You mean the IMU?  What about the compass?  

i have calibrated the compass fully. P2 rotates 360 degrees horizontally -> green indicator light ... I followed the instructions but the green light flashes then red like the video. do you have a way to fix it?

This is how it's done.  Shoot ahead to the 1:45 mark.

https://www.bing.com/videos/sear ... etail&FORM=VIRE

Watch the lamps.

If the calibration fails, rear lamps blink red yellow red yellow red yellow.

If the calibration is successful like in the video, then the lamps will not blink red yellow.  Instead, they will go back to whatever they are supposed to be doing before you initiated the calibration.  Could be anything.   In other words, the lamps go back to normal operation.  

You should calibrate the compass outside away from everything.

If the motors still don't work, and you're sure the gps is working correctly, and you're sure the compass is working correctly, you could calibrate the IMU.  Make sure the drone is perfectly level.  

Good luck

Mark The Droner Posted at 6-18 03:59
This is how it's done.  Shoot ahead to the 1:45 mark.

https://www.bing.com/videos/search?q=dji+p2+compass+calibraton&docid=608006050509052308&mid=932F5FC79B0D2D09A9BF932F5FC79B0D2D09A9BF&view=detail&FORM=VIRE

i ran the system firmware P2 V3.6 again and that fixed the error. Thank you for your help.