Every diagnostic claim needs a traceable source.
Garage Opener Help combines manufacturer documentation with observable homeowner signals. The tools narrow branches; they do not pretend to replace an on-site mechanical inspection.
Identify before diagnosing
Exact model labels beat housing shape. Chamberlain/LiftMaster LEARN-button color is used as a source-backed generation clue; Genie identification prioritizes model and serial labels.
Observe first
Flows start from what the homeowner can actually see: code, blink count, sensor LED state, reversal point, wall-control behavior or manual-door condition.
Verify by generation
The same brand can change behavior across generations. We preserve generation boundaries instead of flattening every opener into one answer.
Prefer manufacturer sources
Official support pages, manuals and current compatibility documentation are the factual baseline. Secondary sources may reveal a question but do not become authority for a diagnostic mapping.
Grade evidence, not certainty
A diagnostic fingerprint labels the current evidence Strong, Moderate or Weak, explains why, and shows what the observations make less consistent. Exact model identity improves applicability but does not prove the failure cause by itself.
Delay replacement decisions
When evidence is insufficient, the tool explicitly says what not to buy yet. Compatibility records are published only when an exact manufacturer-supported relationship has been verified.
Separate opener vs door
If the door is heavy, unbalanced, crooked, off-track or has damaged spring/cable hardware, the flow stops treating the problem as an opener setting.
Record source freshness
Interactive datasets carry a last-verified date. High-change compatibility relationships should be rechecked against the live manufacturer chart before expansion.
Do not flatten source conflicts
If manufacturer pages disagree across generations or support systems, we prefer the most specific current documentation for the represented product and preserve the conflict instead of silently blending both claims into one universal rule.