I have a panasonic mp3 cd player, model number CQ-RDP472N,
I am running 2 front speakers from the head unit, and an amp and sub from the preout. I had to disconnect the amp and was re innstalling it, here comes the stupid part! I forgot to remove the fuse from the amp power cable, and with all the preouts, amp switch wire, and negative connected, I shorted the +ve to the amp casing.
It didnt blow the fuse and the amp and sub work OK, but the door speakers do not.
A friend of mine said he had a similar problem with a kenwood head unit and there was an internal fuse on the built in amp, do panasonic have these?

Thanks for any help, and sorry for boring you:D, Rob.

Yep
Loads of electrical items have very very small hidden fuses.
Engineers Dream!!!