Sounds like your JP1 jumper fell off. Just place it back on.
I wish that was the case but everything in place.
I have dissconnected all, and connected it to one ESC and still nothing.
Check the schottky diode next to that jumper. This channels the power from the output rail to the APM2.
no beep no nothing.
it seems that this diode is dead.
what to do ?
You might want to read this (for the APM1) http://diydrones.com/forum/topics/missing-apm-board-component-diode... to get some ideas..
Find an ouput on the APM that DOES have 5volts and take a jumper wire to connect that to the ouptus/inputs or wherever you needed 5 volt power. That's how simple this is.
For example, the analog inputs have have 5 volt pins likely unused, so does the other 2 UART ports, then there are a number of other locations on the board also silkscreened as 5 volts. You can easily connect all of those with wire to make your own power distribution of 5 volts. Just use common sense that you no longer want to draw power acrosss the APM (put power in on one pin and somewhere else draw a lot of power out, like radio for telemetry, the receiver, sonar, optical flow, etc...). I other words, tie all the 5 volt pins together externally.
Notes of caution:
The diode was in place such that when powered from USB, the ouputs were not normally powered because of the 500ma limit of power from USB. Thus if you tie them together now, then be careful powering via USB, or USB +power from the BEC and Battery.
Or, just replace the diode, but since it's hard to get to and surface mount, the jumper wiring would get you flying quicker.
Had a flight this morning, tried to have another one later, but the board wouldn't power up at all.
Just checked now and the output rail is dead, it'll power up fine with 5V on the input rail. A couple threads mention a diode that may have gone, if this is case I presume its the diode next to J1 labelled B26.
If so what with what do I replace it, I see there's a few different types? (Please note I have the equipment and am fine soldering SMT components.)
What would cause this to happen, nothing has changed now after 100+ flights?
At this point I would say we need to ask 3DR to look at it.
It seems that this diode has a failure or just not the right components.
I have faith in the group that it can be resolved.
I would but it's very expensive for me to send it back to 3DR from my country, not to mention the time involved.
Ok so assuming i would go with power only from the Input Rail.
I probably need some BEC to power the reciver that than powers the board ?
Will this SBEC from HK can do the job well and operate two servos in future ?
That BEC has a poor reputation looking at the comments, at best only 2A. Maybe get something better.
I got an email from 3DR, they only give a 90 day warranty so I can't send mine back. The diode is a MBR0520LT1G and one of my local suppliers has stock and it costs US$0.10.
To send my APM back will cost me $25