APM 2.6 Clone V3.2.1 Unable to arm. Diode/Fuse ok

Hello everyone.

Cliffs are at the end, but the post is more detailed.

I am relatively new to the quadcopter world (but not new to electronics) and recently purchased a APM 2.6 clone kit seen here ebay.com/itm/US-Stock-APM-2- … 51265?rd=1 (I have not set up telemetry). Upon getting the the board I uploaded 3.2.1 via Mission planner and used the setup wizard and configured the APM. I was unable to calibrate my qbrain 4 in 1 esc via the ardupilot, but I read numerous reports of this happening so I bypassed the controller and calibrated directly.

Next, I attempted to arm the copter (throttle down, right) and got nothing. Per the instructions in the setup instructions to discover what was stopping the pre-arm check on the ardupilot website, I connected the USB cable and attempted to arm. To my surprise, it the motors spun. I searched this particular issue online and found that there may be an issue with a diode or the fuse on the board. I pulled the board and followed the instructions posted here by Iaon Ghip:http://diydrones.com/forum/topics/big-trouble-no-power?commentId=705844%3AComment%3A1234237 . Both the diode and fuse check out fine, 5.33V in and 4.97V out the fuse.

Next I ensured the battery voltage was reading calibrated (3dr power module V1) The voltage was reading just over 0.2V off, so I followed the instructions and calibrated the battery voltage. Just to cover all of my bases, I also disable the pre-arm safety check to ensure the lack of GPS lock (attempting to arm indoors) was not hindering me.

The blue led continuously flashes and the red led blinks continuously. The amber led is consitently on. I am unsure what my next step should be. I cannot check for an error code because the quad arms when connected to Mission Planner. If anyone has any suggestions or anything I could be missing, please let me know.

Newer to quads.
Purchased clone kit here:http://www.ebay.com/itm/US-Stock-APM-2-6-Flight-Controller-GPS-3DR-915-OSD-Current-SensorUS-/251790951265?rd=1 (I have not set up telemetry)
Calibrated ESCs bypassing APM
Initial setup through setup Wizard
Unable to arm
Connect to Mission Planner to check error, quad arms while connected to USB
Check diode/fuse - both ok
Verify battery monitor calibration
disable pre-arm safety check - still will not arm
Blue/red led flash while amber remains on
unsure of next step

If you took the time to read this all, thank you. I really do appreciate it.


Update for everyone.

I reinstalled the firmware and was actually able to calibrate the 4 in 1 esc and the motors spun and adjusted as I adjusted the throttle. Now when I attempt to arm the quad, the motors spin briefly and then stop. If I quickly go to full throttle, they will not shut off, but slowly “step down” in rpm. If I am connected to the PC, the motors wil not shut off and behave as yo would expect. To verify that it needs to be connected to the computer for the motors to function properly, I connected the USB cable to a 5V 1A power block and the quad will behave as though it is only connected to LiPo; a few seconds on, then shut down. One thing I have noticed is that when attempting to calibrate (or verify) my power module, there are two “battery_voltage” parameters in the status section. Not sure what is up with that.

Anybody have anything I could try? Any suggestion is welcome. Hell I’ll even try spinning on my head.

I went through and disable every FS parameter and discovered that the battery failsafe is what was cutting the power off to the motors. Going through the full parameters I discovered that there was a battery cut off voltage (FS_BATT_VOLTAGE) and it was set to 14V. Adjusting the voltage for my 3S battery to 10V and the motors don’t shut off after a few seconds.