The yellow LED is flashing

"(1) One quick flash: Overcurrent in the motor or drive circuit. Let the device rest, then try turning it on. If it starts up, the device will return to normal; if it fails to start a second time, please arrange for a replacement.
(2) Two rapid flashes: Motor wire breakage or damaged drive circuit. Send for repair or replace the unit.
(3) Three rapid flashes: Motor startup failure. This may be caused by the hair dryer overheating due to a blocked air intake or exhaust vent. The unit will automatically shut down for protection when overheated. Instruct the user to clean the filter, let the unit rest for 5 minutes, then restart it; if it fails to start, send for repair or replace the unit.
(4) 4 rapid flashes: Motor overload. The device’s motor is overloaded. Instruct the user to let the device rest for 20–30 minutes before using it again"