Tumble Dryer Tripped the Circuit

Your tumble dryer keeps tripping the circuit breaker and you would rather not call someone out blind. Give it when it trips, the type and age, and this walks a fault tree: overloaded drum, blocked vent, failing heating element, worn motor brushes, capacitor failure. For each it tells you the confirming symptom, whether you can safely test it with a multimeter, and when to stop and call an electrician.

My tumble dryer keeps tripping the circuit breaker. It trips {WHEN_IT_TRIPS} and it's a {DRYER_TYPE} dryer. The machine is {DRYER_AGE} years old. Walk me through a fault tree covering: overloaded drum, blocked lint filter or vent, failing heating element causing a short, worn motor brushes, and capacitor failure. For each branch tell me what symptom confirms it, whether I can test it safely with a multimeter, and whether it's a DIY fix or one to hand to an electrician.