A while back someone was talking about the use of magnets near their electronic sewing machines. I emailed Brother, Inc. about magnets near the machines and this is the reply:
"Thank you for taking the time to write to us.
You can use a magnet in the sewing area only. A magnetic should never be placed near the main board or the LCD screen. A strong magnet should never be used.
We hope this information will be useful to you. If we can be of further assistance, please let us know."