[SOLVED]Managed to kill the radio

[BillyBag2]

I have managed to kill the radio, not sure how. (rev D) When it is plugged in there are now no lit LEDs. Not found by PC.
It looks like D1 is high impedance. One side 5v, the other side is 1v. 1v at the voltage reg and 1v on the 3v3 side too. No shorts in that area measured with a MultiMeter when unpowered. I will look into this more and think I may be able to fix it using D2, assuming there is no underling issue.
Will try it on a bench supply to monitor current.

Plans include, supply 5v to the unfited programming port. If this works wire USB 5v to the port, I have no intetions to use the port and it is easier to solder. A fiddlier fix would be discard D1 and replace with D2. (D2 requires a 180 twist)

Any advice or ideas on fixing or diagnosis very welcome. I will try and keep you posted if I fix it.

[BillyBag2]

Its alive again. Added a header and power it from an external supply. So I attached a wire from the USB 5v to the header and it all appears to work OK. Not sure how I broke it. Looks like just one diode is dead.

[tobias]

Great that you managed to fix it! Maybe ESD was involved, it often is when electronics break for no reason.