Sailing_Nut wrote:Thanks for the information.
It looks like power supply "beef" is my issue. The unfortunate thing is that I have a ton of spare very hefty PSUs around, but getting them mated to a micro USB is an issue.
I read somewhere that you can power the Pi by supplying voltage to pins on one of the headers. Unfortunately, I don't recall where I read it. I am guessing that it is the 5V pin (and of course GND) on the GPIO header, but really don't want to risk smoking my Pi by having a go at it. Does anyone have confirmation that you can power a Pi through those pins? If yes were there any little tricks that you had to use?
Yes you can power the PI through the 5V and GND pinheaders, but be very careful, as this route bypasses the main fuse F3, I would strongly suggest adding your own external fuse, certainly if you use a strong external power supply.
You can measure the power on the board by measuring between the two testpoints on the board TP1 (5V after the fuse) and TP2 (GND). The voltage there should be very close to 5.00 Volt, and no lower than 4.75 V (however for the USB ports you would need more to begin with).
The problem could also be the voltage behind the USB polyfuses (F1 and F2), there the voltage could drop as low as 4.4V. But all low current (100mA or less) devices should be able to work with that, but any lower is a problem, and some higher current devices (more than 100mA) want at least 4.75V just like the PI itself.