Hi Mike,
I'm no expert, and my CD 100 is currently not producing any sound at all, so I can't test out this suggestion, but I think there's a fairly simple fix you could try...
In the manuals when they're explaining how to troubleshoot sound issues (what I've been doing lots of), one of the first steps they advise is to unplug the "mute" plug from the amp. My bet is that if you do that, the amp will no longer mute. Of course this may mean that you get a bit of low level noise through your outside speakers when the CD is changing.
The amp is located on the lower left sidewall of the CD100, the plug is top right on the amp - and (at least on mine) is labelled "MUTE" or similar.
Fingers crossed!
James,
Hove
UK