Other times you turn multiple dials and nothing fixes it, but now you are unsure if something did fix it and you also undid the fix with another dial . . . or if none of it fixed anything. Turn one dial at a time—the most likely candidate first—and then measure the result. Reset that dial and try another and measure that. Turn the dials in sequence until you find the cause, and only after you do the single dial turns, consider multiple dial turns where a contingency may be in place
