I do not have a USB hub or a Netflix box but the fact that when the first one died it still would work with the power suppy of the "good" one makes me think it's the internal power supply.
OK, you lost me...
There is not an internal power supply per se, there are some regulators, but that is it.
The only PSU (Power Supply Unit) is the "wall-wart" or "AC wall adapter" as some may call it.
Are you saying that the when the first one (both the unit and it's wall-wart) died that if you used the wall-wart from your second working unit that the dead unit would then work? If so, that points right at the wall-wart (AC Adapter/power supply).
If so, then you have two dead wall-warts (AC adapters) and you can get them for $9.99 ea at the Roku SoundBridge store.http://soundbridge.roku.com/store.php
Roku3 and Roku HD1000 [Rev B] on a Samsung HLP5674W DLP in the living room; a Roku2 and two Roku XS and a few SoundBridges.Win7; Kubuntu and XP via RT-N66U, E2000 and a switch or two. I own stock in Roku, it's just all in the form of hardware.Viva la Roku