Some methods require desoldering or using a clip on the PLC’s internal memory chip to read the hex values where the password hash is stored.
You can perform a factory reset by creating a specific file on a standard memory card: Create a text file named S7_JOB.S7S on a formatted card. Write the text factory reset inside the file. Power off the PLC, insert the card, and power it back on. s7 200 smart plc password unlock work
The OEM almost certainly holds the master password, which was set during commissioning to prevent unauthorized modification of their proprietary code. Some methods require desoldering or using a clip