I recently bought an Acer Aspire ES1-512. I wiped the disk and installed Xubuntu 15.10 64bit (dual boot with Windows 7 – BIOS, not UEFI).
When I started using Xubuntu, I realized that at random points, it completely freezes with the screen retaining it's contents but nothing being responsive, and the only possibility being to hold the power button and force a restart.
I also noticed that initiating a shutdown or a restart or a standby all result in the same problem (the freeze).
To test whether older versions of the OS don't have the problem, I tried installing a bunch of them on a flash drive and trying a live boot. All of the versions 14.04.3-desktop-amd64 / 15.04-desktop-amd64 / 15.10-desktop-amd64 had the same problem (freeze on shutdown), however 14.10-desktop-amd64 shuts down successfully.
Any suggestions?
EDIT: I tried turning off ACPI by adding acpi=off to /etc/default/grub, and I noticed that this solves the random freezes, but it didn't solve the shutdown/restart problem. Also, turning off ACPI disabled some features like keyboard media (fn) keys and the built-in MMC card reader as well as the battery meter, so this is not a good solution..
EDIT: I tried a memtest for 10+ hours and it passed.
Best Answer
There have been reports of Acer laptops failing to shutdown or restart properly with some recent kernels. Disabling XHCI USB3 support in the BIOS seems to workaround the issue. This will have the disadvantage of slowing down any USB3 devices to USB2 speeds. It is probably the same USB3 issue reported as bug #1485057 which is likely to be fixed in recent kernels, so you could installing a recent mainline kernel instead of disabling USB3.