When something is dead, follow power from source toward the load.
Start Here
Confirm the supply.
Inspect plug and cord.
Check fuses and interlocks.
Verify the control can request the load.
Check the load and its wiring.
Most unnecessary repairs begin with a real symptom and an unsupported conclusion. When something is dead, follow power from source toward the load. For the power-path method, concentrate on the diagnostic process itself. 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: confirm the supply, then inspect plug and cord. 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 fuses and interlocks. Then decide whether verify the control can request the load 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 jumping straight to the most expensive part, ignoring neutral/return paths, and bypassing safety devices for normal use. 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 confirm the supply.
Remove external causes first; specifically verify inspect plug and cord.
With power isolated where required, inspect check fuses and interlocks and then evaluate verify the control can request the load 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
Jumping straight to the most expensive part.
Ignoring neutral/return paths.
Bypassing safety devices for normal use.
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.