Kubuntu 15.10 freezes after sitting idle

Hey everyone. So I just installed Kubuntu 15.10 to replace Windows 7 because I kept getting a weird BSOD after doing file operations (copying/pasting/etc) over the network to and from my laptop. This computer is used as a file server mostly so I need stability. I'm working on figuring out some other issues right now, but two nights in a row I've noticed when I go to use the computer in the moing, it's frozen. Usually I have Firefox, terminal, and maybe system settings or Kate left open, since Ive been setting things up. But when it's frozen, the mouse cursor doesn't move, hitting NumLock doesn't tu it off or on, so the only thing I can do is painfully hold the power button down to shutdown and tu it back on again.

About the computer...
AsRock Q1900-ITX (embedded Intel Celeron J1900)
4GB G.Skill Ripjaws
Kingston V300 SV300S37A/120G 120GB SSD
Weste Digital Blue WD10EZEX 1TB HDD (2 of these)
LG WH14NS40 Bluray Buer
Seasonic 360W Power Supply

I had issues installing Kubuntu and found I need to boot EFI and that fixed that problem. So now Kubuntu boots from the SSD in UEFI like apparently Win7 did. I think that's all the info I can think of atm.

I've seen older threads about a problem similar to mine, but they were much older versions of Ubuntu. Updating the keal seems to fix the issue in other threads, but my system says it's up to date. Also, a lot of threads go unanswered or beyond my knowledge of Linux. Not sure what other info anyone might need to help figure this problem out, but just ask and I'll do my best to provide the info.