Thanks for the response

Yes, that's right. The plug does seem to be the problem. The thing is: I don't know what plug I should use. It wants 16vdc, so I got that. When it didn't fit, I said, well that's fine, I'll just find one that does fit. Looking at the stores online, 2.1mm for the center pin and 5.5mm for the outer cylinder seems to be the standard for 16vdc power adapters. So I just don't know what size I'm supposed to be looking for.

Incidentally, I'm not really sure if it's too small or too big! It looks like it should fit, but it just doesn't!

Thanks again!