Hello All,

I recently did a teardown of my A2 and Tarot 680Pro to do some upgrades, Before the teardown I had difficulty entering the compass calibration via the GPS-MANUAL-GPS switching as described in the manual, only successfully entering calibration 2 times since it was initially powered up in the spring of 2014. After my rebuild now, I have a compass calibration error, I cannot enter cal mode, and my LED module emitts nothing, at any time. No lights on initial power up, no lights when connecting USB, nothing at all. I can connect to the controller via USB and Bluetooth, and the small bluetooth LED on top of the module by the USB connection emits what appears to be an alternating red/yellow indication.

While torn down I connected all of the A2 modules on the bench, powered the system up and performed software upgrades as required about a month ago, the LED module worked at that time.  

I have ordered a new BT/LED module hoping it is the problem, hopefully tomorrow I will find out, and post information here for everyone.

Ok so the LED/BT module plugged in and worked. I have no idea what happened to the old module but this one worked great. I was also able to enter compass Cal the first time. successful flight after 6 months of downtime and beating up my F450 just because I can!