[solved?] Hello, I have experienced this issue on two E6520 laptops with i5 processors running the Linux Mint live image for installing Mint version 18 (booted off the USB port.) Both laptops running BIOS version A19, which is the latest version at this time. In my troubleshooting I found this issue continues to happen despite removing the hard drive, cdrom drive, and despite switching from a low quality USB 2.0 thumb drive as the boot device to a high quality USB 3.0 thumb drive. This issue seems to be the same as what is discussed here: http://en.community.dell.com/support-forums/laptop/f/3518/t/19579391
My preliminary testing indicates that the solution may be as simple as ... choosing the option of "Load Defaults" in the BIOS. When you choose this option, you will also be asked if you want to allow the SATA Operation to be changed. I suggest selecting "NO" for the SATA Operation change. Then press "Apply" to confirm the "Load Defaults" command. As far as I can tell, there is no specific setting or combination of settings in the BIOS which causes this issue. That is to say, I am so far not able to replicate this issue after choosing to "Load Defaults" despite the fact that I have set all the BIOS settings back to what they were before choosing to "Load Defaults." Therefore, I think that "Load Defaults" may be clearing up some corruption in the BIOS settings. If this is the case, then it is in theory possible that the BIOS corruption happened due to an upgrade of the BIOS, or a low NVRAM battery. A low NVRAM battery can be tricky in some laptops because it may not cause problems until the main battery is removed from the laptop which leaves the NVRAM totally dependent on the NVRAM battery. I have tested for several hours after loading defaults, with no further crashes. Before loading defaults, I would get at least a couple crashes per hour while doing nothing more than navigating the GUI. I will update this comment if I find any new info or any info which contradicts my preliminary experience so far. x84 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1580692 Title: Dell latitude e6520 display freezes must reboot To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1580692/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs