wrote in message
I checked the heating element (about one year old) with an ohm meter
and it seems to be perfect (~10 ohms).

I now believe that the problem must be in one of the parts that I
*didn't* replace (amazing how the manufacturer programmed the machine
to be replaced after 10-12 years...). Probably something in the
control mechanism (or themocouple?).

My question is: how do I pinpoint the exact part that needs
replacement so that I can order it?

Try the diagnostic aids at www.applianceaid.com or www.repairclinic.com