We haven't found the Thermador columns to be that hard to work on. Almost the entire unit can be worked on from the front and the control boards slide out on a pull out divider. It takes about 30-40 minutes to change a main control on these units.
The icemakers will show error codes so you know whats wrong before having to pull them.
I don't know who you had work on them but they must not have attended any of the trainings.

they replaced the icemaker and then the circuit board - and it is still not working. my husband always suspected the optic switch - how can you test for that?

Sorry you are having problems. We haven't in the 4 years we have had ours. I will say that the ice drawer has to be pushed in completely. It seems that if it is even out a fraction of an inch it won't produce ice. I always push mine in then give it an extra gentle little push to make sure it is seated.

It sounds like you have had parts replacers insteasd of technicians, I noticed you wrote that they tried level 1 and level 2 stack Bosch support. Since Thermador does not have this is it possible you had an A&E tech. A&E is kind of Sears techs and they use the Sears STAC as their service support instead of Thermador. I call straight to the Bosch Thermador techline and they don't have a level 1 or 2.
Anyway there is a light beam under the icemaker that flashes and you count the flashes to get the error code.

Try calling Thermador customer service and see if they have a different servicer for your area that can contact Thermadors techline. They should be able to figure out your problem pretty quick.

@jakvis - I had my fill of technicians and think I can fix this myself much faster than the five weeks this has been going on. I think I see the "beam-opening" just above the rocker-switch but there is no light/beam emitting from it and therefore no flashes to count, unless it only flashes when diagnositcs are run. Can you advise further?

HELP - are there experienced technicians in the Raleigh NC area - they have replaced ice maker, main board - they think it might be the sensor - but no one knows how to replace it -

To see the light flashes you need to tape the main door light switch closed and then reach back under the icemaker and push the little rocker down so you can see the light flashing. The rockers job is to block the sensing beam when the bucket is removed.

Works for me! I'm having so many problems with my freezer column

We had the freezer column start beeping when it was just two years old - the Theramdor tech ended up replacing both modules. Now, 3 years later it's doing the same thing and the same Theramdor tech has ordered the same replacement modules. There is clearly a design flaw with this freezer. Similarly our Thermador oven needed to have three modules replaced after 1 year. We will never buy a Thermador again! Ever, ever, ever.