Screen Timeout Doesn't Work

I have an old laptop Satellite S75Dt-A7330. The screen timeout has never worked properly. I have it set for 3 minutes and the desktop icons disappear but the screen stays lit. Any suggestions will be appreciated.

 

1. Check the power settings. Make sure that the screen timeout setting is enabled in the power settings. To do this, follow these steps:
   
   • Open the Control Panel.
   • Click on System and Security.
   • Click on Power Options.
   • On the left side, click on Screen timeout.
   • Make sure that the On battery and Plugged in settings are both set to a time that is longer than 3 minutes.
2. Update the BIOS. If the power settings are correct, then you may need to update the BIOS. The BIOS is the software that controls the hardware on your computer, and it may contain a fix for the screen timeout issue. To update the BIOS, you will need to download the latest BIOS update from the Toshiba website and follow the instructions in the update file.
   
   
3. Reset the CMOS. If updating the BIOS does not fix the issue, then you may need to reset the CMOS. The CMOS is a small chip on your motherboard that stores the BIOS settings. Resetting the CMOS will restore the BIOS settings to their default values, which may fix the screen timeout issue. To reset the CMOS, you will need to follow the instructions in your laptop's manual.