Unit hums but doesn’t rotate → Check capacitor (Step 1) → If capacitor good, check starter switch (Step 4) → If switch good, motor rotor is seized (Step 7 – requires rotor extraction tool, see page 22).
(often associated with ASSA ABLOY swing door or garage door operators), here is a helpful summary and where to find the technical documentation. The Crawford Automatic 300 SE crawford automatic 300 se manual extra quality