It may happen that during the use of the 7701M in the CADR program the error "Error code 239 EF" appears. This error is related to the sticking of the magneto-optical head.
The fact is that the silicone on the new device "sweats" and can hold the magneto-optical head. This problem can be exacerbated by temperature, humidity, damp ink on banknotes, etc. However, the sticking effect usually decreases as the silicone surface becomes dusty and wears down.