For informational purposes only, this is what I did to fix my intermittent power issue. First and foremost, if the unit is under Warranty, Send it back! If you take it apart and blow static sensitive components, you will own it. Secondly, if you do take it apart, you do so at your own risk! This worked for me but I make no claims about it working for anyone else. If you do proceed, then be sure to use a static sensitive work area and wrist strap.
Here is what I did. (watch how you take things apart because it will be how you put it together)
1) Remove the SD card and next remove the 4 screws on the rear case.
2) Using a small pocket flat screwdriver, slowly work the front bezel free from the case (it snaps together)
3) Remove the front bezel with LCD. Take care not to over flex or break the flex circuits.
4) Remove the 4 screws that attach the board to the rear case. Slowly separate the board and rear case, noting that the flex circuits are still attached. Also you'll have to slide out the small little board on the top.. It is connected by a wire. Next, I marked the top side of the two speaker connectors, removed them, and set the rear case assembly aside.
5) You now have access to the soldered female receptacle on the board. For my Ifly700, this was a black box shaped component, soldered to the board in 4 places.
In my case, I noticed crystals around the solder joints. This was cleaned using a que-tip and IPA (alcohol). Next, if you look into the receptacle, you’ll see a pin and the metal wiper that makes contact with the power plug OD when inserted. I reached in from the back of the receptacle with a dental pick and gave that metal wiper just a little more of a tweak to assure a good ground.
Finally, this last step, which in my case I believe to be the big winner, fixing the center post. When you looked into the female receptacle soldered on the board, you noticed the male pin. Well this male pins goes into the female part of the power plug when connected. On my device, this pin was swaged onto the metal portion of the board mounted power receptacle. What I did was access this connection from the backside of the board mounted power receptacle. Not much room here, but if you look you’ll see the pin connection. I fluxed this using a Kester flux pen and then soldered it solid. I am 100% confident this was the root of my problem. (Previously, I had put a black magic marker stripe on the power plug. When I inserted it, it wiped fairly well, telling me it wasn’t a ground issue. It was a board or center power issue…)
To re-assemble,
1) connect the rear case assembly speaker plugs to the board noting the way you took them out... (tight fit here),
2) insert the main board and small board into the rear case and attach with the 4 screws (you have to sorta jockey the plugs into position). Make sure the silver square foam between the two boards are touching. This make a ground I believe.
3) Carefully fold the front LCD and bezel and snap together to the rear case assembly.
4) Install the remaining 4 screws.
5) Insert the SD card.
Good Luck and let me know if it helps…!