My electronic SM has batteries (2 sz. AA) to support the computer memory. Your SM may have batteries also. I recently had occasion to change the batteries, per the message on the LCD display. I happened to notice that one battery had a slight roughness at one terminal. This makes me think it was early stage of corrosion. The batteries last for years on my Pfaff, so I could go quite a while without handling the batteries and noticing any deterioration. Maybe the technician check this when the SM is serviced, maybe not. From now on, I will check my SM batteries about once a year. I am making a note on the last page of my calendar, where I write reminders for the next year. We have a very humid climate here, but I would think it may be useful for anyone to keep an eye on the batteries. The SM manuals usually have information about accessing the batteries. This public service announcement was brought to you by:
PAT in Virginia