SOIC-8 Bios Chip localisation / identify.
With this instruction it should be easy to find / identify the Bios chip on the board. For notebooks a distinction has to be made between systems with one Bios chip and systems with two or three BIOS chips. Modern laptops often have a second or third chip, which performs the tasks of an EC / KBC BIOS. Motherboards have in most cases only one Bios chip. Only a few motherboard manufacturers such as Gigabyte use a second chip (for Gigabyte motherboard the second chip is a Backup Bios).
Systems with one Bios Chip:
SOIC8 (200mil) Bios Chips are mostly soldered directly on the maiboard! This chip configuration/ package is slightly larger than the other chips with 2x4 pins on the mainboard. Due to the compact design of the current devices, the Bios chip is not necessarily located near the Bios battery.
Most manufacturer mark their chips with a small paint dot or a sticker. Most frequently installed chips are those made by the four major manufacturers Winbond, Macronix, SST or cFeon. In addition the number 25 is often use in the designation.
Should the designation not be visible due to impurities or adhesive tape, you can clean the surface of the chips with nail polish remover or isopropyl.
A few examples of Bios chip designations for SOIC (200mil) configuration/ package: SST 25VF016B, SST 25VF032B, SST 25VF080B, Winbond 25Q32BVSIG, Winbond 25X80AVSIG, MX 25L1605-DM2I, MX 25L3206E, cFeon F32-100HIP etc.
Picture: Bios Chip soldred.
Systems with 2 or 3 Bios Chips:
Notebooks with two or more Bios chips have additionally to the main BIOS chips an Embedded Controller (EC) or a Keyboard Controller (KBC) chip. This chip can have the SOIC-8 (200 mil) design or often the SOIC-8 (150mil) design.
The Embedded Controller (EC) or Keyboard Controller (KBC) Bios have, among others, the following tasks:
-switch on/ off function for the notebook
-keyboard commands control
-battery charging control
A few examples of Bios chip names with SOIC (150 mil) design:
PM25LV010A, Pm25LD512, EON F10-100GIP, Winbond 25Q10BVNIG, Winbond 25X10BVNIG, Winbond 25X20BVNIG, MX 25L512AMC, MX 25L1006E, MX 25L1005A
Picture: SOIC-8 200mil Chip (red arrow) and SOIC-8 150mil Chip (blue arrow) soldred.
The other configurations/ packages will not be described at this point as they are mostly used only once on the mainboard and can be located easily. ( see Bios Chip package)