Scotsman CME1202 - Manual (Page 33)

Sonar Service Diagnosis
 Transducer Check
 Switch power on and check the transducer against a hard,
flat surface.
 Try a NEW transducer, if that does not fix the machine,
replace the BOARD, but re-use the original transducer.
–
It is VERY UNLIKELY that BOTH the transducer
and the BOARD have failed at the same time.