I've brought a N505 off eBay, got it cheap cos the headphones don't work properly, thought it would be a quick fix, turns out it's a bit more complicated than I thought.
The problem isn't with the headphones or the internal connector. For some reason the beeps and the timer alarm work fine, just not the music. I've found the cause of the problem though.
Look at this pic http://notacake.com/minidisc.jpg
I'm not exactly sure what that is but it seems like a switch. It was originally covered with a round rubber pad the was being pushed down by the back of the case, but the case had dug into the pad too much and was no longer applying enough pressure. When pressure is applied to this switch/chip the sound comes on. I've tried replacing the rubber pad with other rubber/foam pads but it doesn't fix it for long.
Is this a common problem? and more importantly, how can I fix this permanently? It doesn't seem to be actually broken, so I don't see any reason why it can't be fixed properly, I just can't think how....