I have quite a few WRT54G (x) boxes and quite a few RV042s as well. I just recently discovered that the power adaptors ("wall warts") are of two very different types: One is marked for output of 9VAC 1000ma Another is marked for output of 12VDC 500ma. Normally one must match with either DC or AC - they don't mix in general. I tested the adaptors with a simple voltmeter and got this: 17.5VDC for the 12VDC model and 40VAC. 10VAC for the 9VAC model and 0VDC. These results make reasonable sense in that a DC output model could still have a lot of ripple at the output - which would look like AC voltage to the simple meter. And, the higher reading of 17.5VDC could be caused by the ripple affecting the meter reading. And, 0VDC out of an AC to AC adaptor is exactly what one should get. The average of an AC voltage is zero. So, it appears that some Linksys boxes expect to be fed with DC. If so, there would be no "transformer" inside the box because transformers don't do DC - unless the circuitry is more complicated. But, why do that? And, it appears that some Linksys boxes expect to be fed with AC. If so, there would be some rectification inside because all the board electronics have to run off of DC of course. Then there could also be a transformer inside. If there's a transformer inside and simple circuitry for power then applying DC to one of these would likely get not much useful power unless the ripple is really high - which it appears it could be! If there's only a rectifier inside then either AC or DC might work fine. Anyway, I'm left with the quandary: which power adaptors go with which Linsys boxes? Is that information available anywhere?