So, basically ever since I've installed Mavericks (way back at 10.9.0) my machine will sporadically hard freeze. By that I mean, the cursor doesn't move (no spinning beachball, it just is locked), the keyboard is unresponsive, the clock doesn't move, when I close the laptop lid the backlight just stays on forever. I have to hold down the power button for four seconds until it turns off to reboot. Anyways, recently I took it in and they were more than helpful, replaced its logic board, and unfortunately the screen (had a samsung panel that was replaced w/ lg rev 2) because apparently they felt there was something wrong with the wifi antennas..... Alas, it didn't fix the problem, same ol' *****.... It seems to always happen sporadically when I'm doing nothing, maybe using my trackpad to scroll in safari or finder.... I suppose it is worth mentioning that once I had an issue with my trackpad that they fixed, it was just sort of jumping around by itself without any usage..... They ended up replacing the top case, battery, and trackpad (because they were all glued together) and that did fix that problem... shortly thereafter upgraded to mavericks, have had this issue.... can happen anywhere from once a day to every week or so, it's real sporadic... Not sure if it happens to be related to safari, I often have it open... Have looked in the console, really see nothing specific happening w/ any given freeze.... It's really frustrating, I don't think I can sell the thing in good conscience knowing that it freezes like this... I feel like I'm stuck with this damned laptop until April of '16 or whenever the warranty wears out..... Any suggestions? (I'm not super enthusiastic about the idea of reverting to Mountain Lion, which I ran for about 5 months w/o issues after I bought it, because its UI performs abysmally in comparison to Mavericks) BTW it's an early '13 15" 2.7ghz/16gb ram/512gb ssd.... (paid like $3k for this PoS....) meanwhile my cheap '12 mac mini has 100 days of uptime.... blargh.