no power to DVD

I've been trying to fix my Navi which was turning on but not reading the disc.

i bought a new DVD drive to swap out, but while I was waiting for it to arrive, now the DVD player isn't turning on at all, which means I can't get the disc out of the old drive. and I don't think the new drive will work if the main unit isn't powering up.

elsewhere I read that I can check the fusebox. but where is it and what fuses should be checked for the Navi dvd player?

and aside from fuses, is there something else I'm missing?