Walk a symptom to a probable cause.

Answer the questions below as you observe them. The decision tree was built from the failure modes documented in the Sumner Series 2000, 2400, and Eventer operator's manuals — every leaf links back to the parts and procedures elsewhere in this manual.

When to escalate

If the troubleshooter doesn't resolve it.

Most field issues are covered by the five repair procedures and the parts catalog in this manual. A few categories of problem warrant a call to Sumner's customer service department or a return to the manufacturer:

Bent or dented mast. Aluminum mast extrusions cannot be field-straightened; the metallurgy is permanently affected. Replace the mast section, or replace the lift if a section isn't available for your serial range.
Cracked weldments. Any crack in the carriage, base, or outrigger weld points is a safety-critical defect. Take the lift permanently out of service.
Recurring brake failure. If you've replaced the brake disc twice in a year and it's failing again, the failure mode is upstream — usually heat from over-cycling, oil contamination from over-lubrication, or a misassembled ratchet causing brake chatter. Consult Sumner support before replacing the disc a third time.
Cable failures more than once a year. Look for the cause: misaligned sheave, corroded environment, side-loading from improper rigging. Replace the cable, but also fix the cause — otherwise you're treating the symptom.