Wilso wrote:... I've got the right jack, it must be the power requirement.
That'd be my guess. Lemme know what happens when you get a power supply. You might be able to order one from your speaker's vendor website, but a good electronics seller oughtta have a generic one that'll do fine ... many are made to accept interchangeable power tips, accommodating a wide variety of applications, so finding one that fits your speakers shouldn't be too much of a trick (you might wanna take 'em to the electronics seller to make sure you get the right plug). You wanna make sure the transformer's voltage is correct, that the power supply is capable of supplying more amperage than the speakers will require, that the transformer's output plug fits the power-in jack on the speakers, and that the plug's polarity is correct.
And actually, half-way decent 'puter speakers are pretty cheap; might not be a bad idea just to bite the bullet and pop for new ones.