If you're using the Chinese version (the "CR" or "SR" series), ensure your language settings in Micro/WIN SMART are correct before attempting to communicate, as connection errors can sometimes be mistaken for password lockout.
This is the most common way to remove a hardware password using the STEP 7-Micro/WIN SMART software. s7-200 smart password unlock
Power on the PLC and wait for the status LEDs (typically the RUN/STOP LED) to finish flashing (usually about 10 seconds). If you're using the Chinese version (the "CR"