Most machines refuse high-speed spin if water remains or the door is not proven locked.
Start Here
Prove the tub drains fully.
Rebalance the load.
Check door/lid lock behavior.
Inspect drive belt where accessible.
Turn the drum by hand unplugged.
The fastest way to get lost is to remove parts before you know which function failed. Most machines refuse high-speed spin if water remains or the door is not proven locked. For washer will not spin, concentrate on the fill, wash, drain, lock and spin sequence. Use every working function as evidence: if one stage still behaves normally, that fact eliminates causes that would have stopped the appliance earlier in the sequence.
Observe the timing before touching anything. Note what happens immediately after Start, what changes just before the fault, and what remains normal afterward. Lights, relay clicks, water movement, motor or fan sounds, heat, vibration and error codes are useful only when tied to a point in the cycle. A fault that appears instantly is a different problem from one that appears only after the machine warms up or reaches a later stage.
Begin with the cheapest conditions to verify: prove the tub drains fully, then rebalance the load. Do not merely glance at them. Compare the actual condition with the manual, correct anything obviously wrong, and retest before moving deeper. Simple installation, maintenance and user-setting problems regularly imitate failed electrical parts.
If those checks pass, move to check door/lid lock behavior. Then decide whether inspect drive belt where accessible can be evaluated safely with power isolated. Choose one test that answers one question: blocked or clear, open or closed, free or jammed, intact or electrically open. If a test result would not change your next decision, the test is probably not worth doing.
Avoid replacing the motor first, testing with a severely unbalanced load, and forcing the door lock. All three skip evidence and can turn a minor fault into an expensive one. After a correction, reassemble guards and connectors, restore normal settings, and reproduce the original operating conditions. A single successful start is not proof; the original symptom must stay gone through the stage that used to fail.
A Safe Step-by-Step Check
Document the exact symptom and pay special attention to prove the tub drains fully.
Remove external causes first; specifically verify rebalance the load.
With power isolated where required, inspect check door/lid lock behavior and then evaluate inspect drive belt where accessible only if it can be done safely.
Reassemble fully and run a controlled test under the conditions that previously caused the fault.
Common Beginner Mistakes
Replacing the motor first.
Testing with a severely unbalanced load.
Forcing the door lock.
STOP AND GET HELP: If the next useful test requires exposed live mains, defeating a safety interlock, opening a sealed refrigeration circuit, disturbing gas controls, or entering a microwave high-voltage section, the diagnosis has reached the professional-service boundary.