I just got this lovely little Sanyo from Ebay for only 11 Euros. Unfortunately the woman who sent it didn't use any sort of padding/bubble wrap whatsoever. It was just rattling around inside a big paper envelope , and consequentially it was very bashed up when it arrived. I managed to put all the pieces back together and it works OK. The wheels turn and the lights come on but there is no sound whatsoever from the speakers or headphones. I know the radio and tape functions all work OK as I made a test recording and played it back on another machine and it sounded fine. I've had a poke around inside but cant see anything broken or loose. I'm at a loss now .
That drives me nuts, I received a nice portable player a few weeks ago, shipped in the thinnest bubble envelope and it had a straight mark across it, like it got run over by a wheel which crushed the packaging. Luckily it missed the player and it's in great condition. I can't see the volume control on yours, maybe that got knocked loose.
I have one like yours and it doesn't work. Sorry I do not have the answer to your question but did you change the belt? Does it require soldering?