Posts on 2012 Mac Mini Wake/USB Problems in OS X 10.10.4
Last Updated: July 15, 2015 (Link to Mac Mini EFI Update for this problem)
Update: On July 15th Apple posted a Late 2012 Mac Mini EFI Update 1.8 that lists a fix for the problems reported with the previous EFI (bootrom) MM61.0106.B08 from the 2015-001 EFI Security Update (included with OS X 10.10.4):
"(Late 2012) Mac mini EFI Firmware Update v1.8
This update is recommended for Mac mini (late 2012) models. This update addresses an issue that may prevent a USB keyboard from being recognized after the system wakes from sleep.
Post Date: Jul 15, 2015
File Size: 4.8 MB
System Requirements: OS X v10.8.5, v10.9.5 or v10.10.4 and later
Applied the update from the downloaded dmg (verifying D/L first) on my late 2012 Mini that had the previous (.B08) update. Bootrom version after the EFI update 1.8 is MM61.0106.B09.
Saw a few reports that the update didn't work (bootrom was still .B08 after the update restart). Normally you should see a progress bar fill in as part of the bootrom flash update process on restart. If not, verify the boot drive format is GUID partition scheme and disconnect any unnecessary external devices. (For major problems after an update, try a safe mode boot or Recovery mode.)
(Notes/posts from original article follows - before the EFI Update 1.8 was released.)
I mentioned earlier that I'd updated a 2012 mac mini's bootrom (MM61.0106.B08, EFI security update) in 10.9.5 (along with security update 2015-005 and Safari update) and haven't noticed any problems yet, although it's not used very much. I was asked to post threads on problems from 2012 mac mini owners that installed OS X 10.10.4 (including EFI security update). Below are links to Apple forum threads from 2012 Mini owners on OS X 10.10.4 USB/Wake problems. Some suspected the .B08 EFI update, saying even reverting back to OS X 10.10.3 didn't help.
I haven't read every post but assume the usual tips were mentioned/tried. (Disconnecting/reconnecting USB devices, test with safe boot, remove 3rd party addons, reset SMC, check system logs, reinstall Combo Update, etc.)
I could have missed it, but didn't see any similar threads from 2012 mini owners with the EFI security update running OS X 10.9.5 in either the mac mini or Mavericks Apple forums. (Update - Just noticed a new thread tonight in the mac mini forum titled Mac Mini won't Sleep since updating Mac EFI Security Update 2015-001. Didn't note OS version but guessing it's 10.9.5 or 10.8.5 since he didn't mention updating to 10.10.4. From his comments "at night will shut down and in the morning I will physically have to turn on", it sounds like what was discussed shortly after the late 2012 mini was released - it would hibernate/shut off after 4 hours of sleep. See previous notes/link on that in next to last paragraph below.)
I'm not using Yosemite but was asked if I'd seen any wake from sleep or USB problems with my late 2012 Mac Mini with MM61.0106.B08 bootrom (from 2015-001 EFI Security Update) running OS X 10.9.5 (build 13F1096 after Security Update 2015-005). I manually put it to sleep for appx 1 hour and it woke OK with no apparent problems. (I have always set Energy Saver to never sleep system or drives.) It's connected to a Yamaha AVR via HDMI for surround sound, with HDMI from the AVR to a (2012) Samsung 1080p HDTV. (Still see 2 display blackouts for a second or two at boot and on wake from sleep, but no issues afterwards. HDMI or HDCP handshaking I assume. Not tried a direct connect to the TV. HDMI control is off for both AVR and TV.) I usually prefer wired keyboards but since the mini is appx 6 ft away, I use a Logitech K400 wireless keyboard (with built-in trackpad) and the included Logitech USB Stub receiver. (No logitech software ever installed.)
After wake, I tested the USB Superdrive (played DVD movie), Logitech Keyboard/Trackpad, Mini's USB hub, etc. - all working OK. The mini has no 3rd party drivers (USB or otherwise) installed and I've always had the built-in Bluetooth turned off since I don't use it. It still has the DIY upgrades of RAM (16GB) and SSD (480GB Intel 520, no trim), with the OEM 1TB HDD used for Time Machine. (I have TM turned Off, and use 'backup now' from the TM menu bar icon as needed.)
And I'm still using the PMSET mods I mentioned in a Feb. 2013 post on why it Powers Off after hours of Sleep (Hibernates/Turns Off) even on AC power. (A 'safe sleep' after appx 4 hrs, originally a 'new feature' introduced in OS X 10.8.2 supplemental update 2.0 per note 2 in this apple doc.) I haven't retested those PMSET tips since then however.
I'll run more wake and USB tests with 10.9.5 over the weekend and post here if I see any problems. (I passed on Yosemite, but plan on trying 10.11 when it's out of beta.)