Originally Posted by LazyZero
Yes, that is more likely. We had same for the Red Brick. They were delivered after a time with different fuse settings which had the same effects. If the ISP programming is disabled by fuses.
But there are alteratives, the 10A UBEC also had some issues with 3s in the past. Look for the DYS 10A, smaller footprint and coming with SimonK bootloader.
Tried different things the last days..no success yet.
Thanks for your help anyway
OT: I think I go for the Favorite Sky Quattro 12A..it comes with BLHeli and a easy config tool...there go another 30 bucks *sigh*