![]() Short the SDA and SCL pins again and keep it shorted.Highlight the Supervisor Password option.Navigate to the Security menu > Password menu.Only the System Supervisor can make changes, then you have not shorted the two pins successfully. If you get a notice BIOS setup is locked. Press ENTER on the keyboard and then un-short the two pins.Short SDA and SCL pins and keep it shorted.Press F1 repeatedly to enter BIOS setup and get the password prompt.Otherwise you'll need to awkwardly poke and prod underneath the keyboard. As some of the steps require the use of a keyboard, you may wish to plug a USB keyboard in to use. If the "Boot" menu mentions "UEFI", then you have a UEFI based system, otherwise you have Legacy BIOS.Ĭhances are you have removed the keyboard to get to the EEPROM chip. You can also enter the BIOS/UEFI setup in read-only mode by using an empty password. You can determine whether your system is BIOS or UEFI based by checking specifications or the user manual to see if it supports UEFI boot. BIOS based systems will be the easiest to bypass, while UEFI based systems may require a few goes before you succeed. BIOS based systems seem to read the password from the EEPROM after the user pushes the ENTER key after entering the password, while UEFI based systems seem to read all the configuration required from EEPROM into memory right after the power is turned on. The procedure seems to be slightly different for BIOS and UEFI systems. We can simply short the SCL and SDA pins together with a conductor such as a flat head screwdriver or a paperclip. ![]() Note that tying SCL or SDA to Ground or Vcc will cause the BIOS to hang, as transitions between low and high are part of the I 2C protocol. We can conveniently tie both the SCL and SDA pins together in order to achieve what we want. This should fool the BIOS into thinking there is no password set. We want to ensure that the only data that gets read out is NULL. The serial clock and data pins are open-drain and are grounded in a specific order for communication to occur. The BIOS communicates with the serial EEPROM through a bus called I 2C. Step 4: Ensure the BIOS reads NULL from the EEPROM when checking the password Pin 1 can be identified by the dot/circle etched next to it (some packages may have a semicircle etched on the edge between pins 1 and 8) and the pins are numbered anticlockwise. On most 8-pin packages, the SDA and SCL pins are on pins 5 and 6 respectively. Step 3: Find a datasheet and/or locate the SLC and SDA pins Also, if you find results for serial flash chips with a capacity of a few hundred K (Kilobits) or a few M (Megabits), chances are that you have found the chip the Embedded Controller or BIOS/UEFI is stored in. Due to the small packages of these chips, the characters marked on the chip may not be the model number of the chip and may be an abbreviation. One with results for a serial EEPROM would indicate the correct chip. To confirm what chip you have, simply read the characters off the chip and Google it. You are looking for an 8-pin Serial EEPROM chip, though it can come in a 5 pin SOT-23 package. Most Lenovo laptops have the EEPROM on the other side of the mainboard (the keyboard side). You will probably need to remove the entire back/base of the laptop or even get to the other side of the mainboard. ![]() Chances are that you won't find the EEPROM behind the exposed parts behind the back cover. Start by removing the back cover of your laptop.
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