Question Author
This may be a bit technical for some people but this is what we have done so far. The liquidiser had still been working but at some time when I tried to put the cover back on it wouldn't fix, so I balanced it on the top and put the mixer away. The next time I used the machine it was just the liquidiser again. All went well until the next time when I wanted to use the mixer bowl.
Thinking something else might be wrong we opened up the machine and had a look. The drive belt is perfectly OK. There was plenty of grease and dirt inside which we cleaned up. We still couldn't get the cover of the liquidiser mechanism to go on. Our conclusion was because the small knob on the point of it did not operate to push down the dog clutch inside. In looking once more at this we realised that this part did not push down the disc beneath it as it should. A slight adjustment to this put matters right. We switched on and with the cover in position the rotor over the bowl started turning. Hurray!!! Now we feel the only thing to do is renew the brushes on the motor as there had been a smell of burning for some time. I had a man out many years ago to do this and I know that you get to the motor from the bottom. I can still get brushes for this machine from several places, even though they'll cost me £10 eaqch plus £5 postage, so now my only problem is, how do I get the motor out to get to the brushes? We will still be trying and I might even find out before anybody else has the answer!
Please forgive me for going on at length like this. I do this just in case there are others with the same problem.
I know some people think this is going to a lot of trouble when I could buy another cheaper mixer but I was brought up to waste not, want not, and I don't want to get another as I don't do that much baking at my age (84).
Thank you all those people who have bothered to try to answer my question.