I think I am going mad :o
I have an Arduino Due board that works perfectly EXCEPT I can't get it to accept a 9 volt power supply via the power jack. You might think that the size of my power plug is wrong but a) I have checked it with lots of other Arduino boards and it works fine b) I have tried other power plugs and different sized barrel connectors and c) the voltage from the 9 volt power supply is appearing correctly on the VIN pin on the board so it must be getting through. When the 9 volts is applied the 5 volt pin measures at about 1.2 volts and the 3.3 volt pin measures at 0.44 volts.
I therefore assumed that the board is faulty and bought another one (!!!) but I get the same results.
I am left with only two possible answers:
- I am going mad, or
- There is a faulty batch of Due boards out there.
I can guess which of these you would pick - and I'd agree with you!