SMW Accu‑Smart 55 is a servo‑drive controller used to command precision rotary indexers and CNC collet systems. Common failure points for this class of equipment include degraded power‑supply rails, damaged or miswired motor/encoder leads, overheating of the drive board, and firmware corruption that can cause loss of communication or erratic motion. First‑check diagnostics: verify 24 V DC input to the controller and confirm all output current limits are within spec; inspect motor and encoder wiring for continuity, shorts, or broken contacts; review any error codes displayed on the panel or logged in the control software for indications of drive faults or communication loss.[oss-gpt-20b]