Sorry to read of problem with your A701A. I am currently writing my own Service Manual for the A701A, for others to use. But cannot use original drawings or text from the original Kenwood Service Manual, due to copy write.
I have completed gearbox removal, strip, greasing & rebuild. Speed adjustment, repairing paintwork & more. Takes a while to do because I have to photograph everything & label parts on photographs, then write & edit clear instructions. A bit like a Haynes Manual. To do this properly I have to carry out all the work myself, before writing instructions.
The bad news is the electrical section is the next thing I will be writing. I may be able to help you though. Can certainly tell you how to remove & re-fit motor using Original Kenwood Service Manual Methods. I offer this as guidance only as I have not yet carried out this work myself.
Options, buy capacitor, resistor, brushes kit, this may not solve problem entirely. Buy re-conditioned or second hand working motor with all electrics confirmed as working. All above available on Ebay.
Have it repaired, I know of these people but haven't used them myself, they have a good name though. Google kenwoodchefrestore or kenmix. Suggest avoid cheap repairers.
If you need information ask on here & I will do my best to help. Will watch this site until 20/6/13.
These mixers are magnificent pieces of British design & engineering. A full mechanical/electrical restoration including paintwork costs vastly less than a new Kenwood I believe now manufactured in China.
Hope this helps.
Roger
June 2013