Re: loose sound to front speakers
Steve, mine did similar with the sound playing from all speakers for a few seconds, then the fronts going silent leaving just the rears working. Eventually I was left with just 1 rear speaker working. It's still that way now.
It's been suggested in other posts that if it's not loose barrel connectors to the radio, it's more likely the amplifier (chips?) which may be the problem and that the unit needs to be sent off for repair/replacement. It's said to be a very costly repair.
I hope I'm wrong in your case .... I'm not technically minded, just repeating what I've read.