"Am wondering if the USB could be a common link among those who have alot of blown regs?
Dirty 5v from their PC?

Can I get some advice on whether this will work for 3.3v supply? Might as well go heavy duty...…"

"Detlef, how were you powering the APM? On the input side?"

"Ok thanks Detlef, back to square one."

"Hi, yep mine was doing the same, only would boot with UBEC already powered then plugging into APM, that's why I looked to see if the UBEC had a spike as that was the only reason I could think of being the problem.

I am using this;…"

"Both mine were bought a month or apart and worked fine for a few weeks before the symptoms.
I would think HK has sold a bucket load of these by now and alot are powering the same as me so we'll see if the reports start rolling in as people migrate…"

"Hi Randy yes it's only milliseconds and my multimeter is a cheap one so it would be good if someone with some good gear to confirm the spike, for what it's worth all my ubecs in parts box did it."

"Ok thanks Randy, I repaired the 3.3v reg like Detlef and all is good, but that is the 2nd HKpilot board with same problem, so obviously it's whatever I'm doing or the board doesn't like the turnigy 3a ubec in the input side with JP removed...
Maybe…"

"Hi Randy, which release will eventually have the new check and change bus speed code?"

"I just went through the reviews of the HKmega on HK's site and a few people have mentioned dead 3.3v regs, I'm wondering if it's feasible to rig a 3.3v ubec in there for durability?"

"Thanks Detlef I'm powering from inputs with JP removed.
Am careful using a UBEC with sub 5.3 voltage."

"Although it does fly fine on pre RC3 firmware so...."

":) No worries, I had advice over at the other forum that all the 3.3v sensors and chips would be damaged by the 5v, and to get a new board, that might be prudent advice...

This is my second board and before my first board died prematurely (pilot…"

"Hi Detlef, thanks I'll order one,I didn't havn't any arming issues, just booting the board requires an already powered ubec, I suspect the startup voltage spike in the ubec is doing something to make the board not arm."

"Hi Randy, it's definitely not normal behavior, on the pre rc's it corrects immediately and is perfectly flyable.
So did we deduce it is a blown 3.3v reg that needs to be replaced?"

"Hi fellows, I joined to say I have similar problems to Detlef.
My board will only arm if UBEC is powered first, then plugged into board.
I checked the 3.3v line today and yes it is 5v also.
I also noticed after a certain rc3-4 firmware my ACC was…"