Separate the cleaning effect from other work

Identify which surfaces were treated and whether any repair, part replacement or sensor work occurred at the same time. Deposit removal changes the condition being compared, but a new sensor mount can also change the recorded response. A wetter or windier post-service interval introduces another ambiguity. Do not assume that every change after a visit was caused by cleaning merely because that was the most visible task.

Investigate the plausible physical mechanisms

Uneven remaining deposits and trapped water raise different questions from coating damage or a changed edge profile. Available images and service findings may help distinguish them. A speed-related vibration feature can support a rotation-linked mechanism without proving mass imbalance. Qualified analysis should match measurement locations and operating states; an overall vibration number alone cannot establish the amount or position of a correction mass.

If cleaning removed material unevenly across blades, establish what remains before considering a correction mass. If cleaning was uniform but another part changed during the visit, the investigation should account for that change. The chronology alone cannot separate these distinct physical hypotheses.

Avoid treating a symptom with weights

Ask whether the blade condition and any retained material have been adequately assessed before a balancing proposal is considered. Adding mass can conceal one response while leaving the actual damage or water path unresolved. Do not repeat cleaning, add tape or perform a run trial outside the approved instructions. No MARSTON balance method, wetness allowance or cleaning-induced vibration limit is asserted; the service decision must follow the identified cause.