Run only the model-supported test or cycle described by Samsung. Record whether the drum turns, the selected cycle allows heat, an error appears, clothes become slightly warm, and airflow is strong at the exterior termination. A dryer that heats but needs multiple cycles often points to airflow, loading or moisture-sensing conditions rather than a total heating failure.
Clean the lint filter and inspect the accessible, cooled and disconnected exhaust path for crushing or obvious blockage. Do not run the dryer with the duct removed as a routine indoor test, and do not reach into a moving blower or disassemble the cabinet. The U.S. Fire Administration guidance makes lint-screen and vent maintenance a fire-prevention step, not merely a performance tweak. If the exterior vent cannot be accessed safely, leave that check for a qualified service provider rather than climbing or moving a heavy appliance.