Exclamation [Q] TF300T won't wake from sleep

I'm trying to help my mother revive her TF300T. She was running the stock 4.2.1 ROM and it was borderline unusable. Task switching was horrible and upon waking from sleep, when that worked, it would be several minutes before it would work smoothly - it definitely wouldn't work when background sync was going on. More often, once it went to into deep sleep, it would have to be manually rebooted since it would not wake. She also had an issue where the volume turns itself up.

I installed CM11 on there and much of the usability problems have been taken care of. It is much, much speedier. However, it appears it still will not wake from deep sleep, at least sometimes. The volume issue persists as well. The latter is probably a hardware issue. I'm wondering if the inability to wake is also a hardware problem. Any ideas?