How to Reset Toshiba CMOS

By Ezekiel James

Your Toshiba laptop's CMOS (Complimentary Metal-Oxide Semiconductor) chip is a small, battery-powered chip built into your motherboard. It stores your computer's date and time settings. Resetting your CMOS chip is a quick and easy way to reset your BIOS settings to their default settings. This is particularly helpful when troubleshooting hardware and software compatibility issues. There are two ways to do this. You can either remove and replace the CMOS battery, or you can set the jumper settings on the CMOS chip to "Clear CMOS." In either case, you have to disassemble your Toshiba laptop to gain access to the CMOS.

Things You'll Need

  • Precision screwdriver kit
  • ESD wrist strap

Step 1

Locate your Toshiba laptop's user manual to guide you through the laptop disassembly process. You can find user manuals for most Toshiba laptops for free from the Toshiba support page (see Resources).

Step 2

Turn off your Toshiba laptop, close the LCD screen, and disconnect the power cable and external devices from your computer. Flip the laptop over and remove the battery from the compartment on your battery pack. Refer to your Toshiba laptop's user guide for more specific information on battery removal.

Step 3

Remove all plastic hardware covers from the bottom casing of the laptop. This includes removing each screw securing each hardware cover to the laptop's bottom casing. Generally, you will be removing the RAM, wireless card, hard drive and CPU covers from the bottom casing of the laptop. Follow the user manual's instructions for removing each hardware device from its respective compartment.

Step 4

Flip the laptop over, open the LCD screen and remove the keyboard bezel with a flat-head screwdriver. The keyboard bezel is a thin strip of plastic between the LCD screen and keyboard assembly. Remove any Phillips-head screws securing the keyboard to the laptop. Lift up on the keyboard and place it face down over the laptop's palm rest. Disconnect the keyboard's ribbon connector from the motherboard. Remove the keyboard from the laptop and set it aside.

Step 5

Refer to your laptop's user manual for detailed instructions on how to remove the LCD screen and upper casing of the laptop. Removing the LCD screen involves disconnecting the LCD video cable from the motherboard and removing the screws from each LCD hinge. Removing the upper casing may require removing several screws from the upper and lower casing of the laptop. This procedure varies greatly from laptop to laptop.

Step 6

Locate the CMOS battery on your motherboard once the upper casing has been removed. The location of the CMOS battery varies from motherboard to motherboard. It often looks like a large watch battery. If you are unable to find the battery, refer to your computer's motherboard documentation. Or, you may have to contact Toshiba directly for more specific information.

Step 7

Remove the battery from the CMOS battery compartment. Do not replace the battery for eight to 16 hours. That is usually the length of time it takes for your CMOS to reset. Or, locate the three-pin jumper switches on your motherboard's power supply. Set the switches to the "Reset CMOS" position.

Tips & Warnings

  • Use an ESD (Electrostatic Discharge) wrist strap during the disassembly process. Doing so prevents electrical damage to your computer often caused by static electricity.