Showing results for 
Search instead for 
Do you mean 

T400 - Screen refresh rate drop to 50Hz when on Battery (Intel)

by ‎06-21-2011 12:14 AM - edited ‎06-21-2011 01:11 AM (1,152 Views)

Question

The T400 screen refresh rate is dropping to 50Hz when on battery despite setting "Never" change Refresh rate when on AC on Lenovo Power Manager.

Answer

Engineering mentioned that this fix can be applied the via changing some values in the inf files. I personally have tested it and it works fine on the T400. Please follow steps provided below, if there are any questions, feel free to drop me a private message on this or post it on the forum.

 

  1. Download latest display driver on the support site.
  2. When the "exe" file is downloaded, double click the file, Accept the agreement and extract it to path (C:\DRIVERS\WIN\VIDEO)
  3. Once the extract is complete, untick the "Install ThinkPad Video Features now"
  4. Click Finish
  5. Click Windows Button, type "run" on the search bar
  6. Paste the following "C:\DRIVERS\win\VIDEO\Packages\Drivers\Display\W7_INF"
  7. Open file named "CW11920.inf" - The file size is 144kb
    Capture 6.JPG
  8. In notepad, press Ctrl + F and search for 0x300 and press enter
    Capture 7.JPG
  9. Change the 0x300 to 0x340
    Capture 8.JPG
  10. Press Ctrl + s to save the changes and close the notepad.
  11. Click Windows Button, type "run" on the search bar
  12. Paste the following "C:\DRIVERS\win\VIDEO\Packages\Drivers\Display\W76A_INF"
  13. Open the file named "C7119200.inf" - The file size is 153kb
    Capture 9.JPG
  14. In notepad, press Ctrl + F and search for 0x300 and press enter
    Capture 7.JPG
  15. Change the 0x300 to 0x340
    Capture 8.JPG
  16. Press Ctrl + s to save the changes and close the notepad.
  17. Once both the files "CW119200 and C7119200" has been changed. Go to Programs and features and uninstall the previous version of the graphic card driver before you install this modded version.
  18. Once the previous version has been uninstalled and the laptop has been rebooted. Follow the steps provided below.
  19. Click Windows Button, type "run" on the search bar
  20. Paste the following "C:\DRIVERS\WIN\VIDEO"
  21. Double click on the "Setup.exe"
  22. Press Yes to install the driver, select the language you want Catalyst to display then click Next.
  23. Click Install
  24. Tick Express and click Next.
  25. You will receive a prompt that Windows can't verify the publish of this driver.
  26. Click "Install this driver software anyway"
    Capture 5.JPG

  27. After clicking install this driver software anyway, the installer will continue to install the drivers and you will receive a prompt to reboot the laptop once it is done. Click Reboot.
  28. The Intel GPU's refresh rate would not change to 50Hz when running on battery.

 

 

 

 

 

Was this information helpful?

Labels
Contributors