Go to www.acer.com
, choose Service and Support, choose Driver Download, choose Drivers & Downloads, select Product Line Notebook, select Aspire 4315, click Search.
The above should get you to here :
Click on "Flash BIOS v1.13 " which is the latest BIOS for the 4315.
Follow the instructions to download and extract the files.
In order to Run the Vv2-113.exe file, you will need to right-click on it and choose "Run as administrator"
Make sure your battery is fully charged before updating a BIOS and do NOT power off the laptop during the update process.
This seems to have fixed most of the white screen problems on the 4315 that I am working on. The Fn-F4 "standby" and power button (or FN key) "resume" process described earlier is worth remembering because I have still had a couple of the white screens with the latest BIOS. Both times seemed to be when the screen saver was trying to start (lots better than during the boot-up!), so I have changed from the Acer default screen saver to something simpler hoping that the change makes the problem less frequent.