Question: Mountain Lion won't wake from sleep
I have a mid-2011 Macbook Air 13". Since installing Mountain Lion (and immediately upgrading to the latest SMC firmware update), the machine will not wake from sleep. When I close the lid, it goes to sleep fine. Upon opening the lid, the screen turns on (apple logo glows on outside of monitor, faint glow from screen), but it remains black, nothing ever appears. Only way to fix this is to hard-reset the machine. Machine was fine under Lion, most definitely related to that upgrade, but still unclear how.
I've tried 3 different things that I found in other forums, hoping to consolidate them here.
1. Reset SMC (http://support.apple.com/kb/HT3964)
2. Reset PRAM (https://discussions.apple.com/docs/DOC-3604)
3. Set the startup volume specifically in the startup disk system preference.
None of these have fixed my issue.
Is this issue more widespread? Seems that others are reporting it on a variety of SSD macs, but that could be a red-herring.
NOTE: this was an upgrade, not a clean install. I will attempt a clean install onto an external bootable drive in a few days to see if this is a hardware/SMC issue, or a Mountain Lion issue, or a 3rd party software conflict problem that crept in during my upgrade.
Any other advice out there?
MacBook Air (13-INCH, MID 2011), OS X Mountain Lion