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APC Back-UPS USB Connection is Causing OS X to Hang at Startup...

I just received the Back-UPS yesterday and plugged my iMac 27 into it last night. After that I connected the USB cable between them to bring up the System Preferences>Energy Saver>UPS settings tab/window and then set >Shutdown Options: "Shut down the computer when the UPS battery level is below: 25%. That's it. Everything seemed fine until I tried starting up my iMac after being shut down. It hangs at the startup screen (black background, Apple logo w/ progress bar). The progress bar gets to the middle and stops. Nothing happens beyond that. It's frozen. I have to do a hard manual shutdown by holding down the power button for 5+ secs. I realized it must be the UPS USB connection since that was the only change/addition made to the iMac. And sure enough, once the USB cable was removed from iMac it started right up. I tried it another time to confirm and got the same result - hang at startup screen.


So what's causing this; OS X, APC UPS, or both? It's obviosuly not the APC SW since it's not installed (OS X not supported - and why is that after all these years?). Why would OS X hang at startup from seeing APC UPS US connection? If this can't be resolved right away, I'll have to return it. The whole point of having this UPS is to protect and be able to safely shut down the iMac (either manually or automatically). And don't say; "Unplug it, then plug in after start up".



APC Back-UPS BE550G

iMac (Retina 5K, 27-inch, Late 2015), OS X El Capitan (10.11.1), 24 GB Memory

Posted on Nov 4, 2015 6:03 PM

Reply
57 replies

Nov 4, 2015 6:59 PM in response to Sapote

Hi Sapote


I have several APC UPSs including the model you are using, and with El Capitan's latest release. It's not causing the problem you describe.


It's obviosuly not the APC SW since it's not installed (OS X not supported - and why is that after all these years?)


Probably because it's not needed at all, since OS X already includes all UPS monitoring and shutdown options required.

And I'd rather not install some unknown open source sw off the internet.


Nor would I. I suggest resetting your Mac's SMC and determining if that changes anything. If not, reset the NVRAM. Procedures below.



Power or other problems related to unexpected system sleep, shutdown, lights or fans call for an SMC reset. Read all the steps.


Before Resetting the SMC


Try each of the following steps in this order before you reset the SMC. Test the issue after completing each troubleshooting step to determine if the issue still occurs.


  1. Press Command + Option + Escape to force quit any application that is not responding.
  2. Put your Mac to sleep by choosing the Apple () menu from the upper-left menu bar and then choosing Sleep. Wake the computer after it has gone to sleep.
  3. Restart your Mac by choosing the Apple () menu from the upper-left menu bar and then choosing Restart.
  4. Shut down your Mac by choosing the Apple () menu from the upper-left menu bar and then choosing Shut Down.


Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve


  1. Shut down the computer.
  2. Unplug the computer's power cord.
  3. Wait fifteen seconds.
  4. Attach the computer's power cord.
  5. Wait five seconds, then press the power button to turn on the computer.


NVRAM reset:


  1. Shut down your Mac.
  2. Locate the following keys on the keyboard: Command (⌘), Option, P, and R. You will need to hold these keys down simultaneously in step 4.
  3. Turn on the computer.
  4. Press and hold the Command-Option-P-R keys before the gray screen appears.
  5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
  6. Release the keys.


After resetting NVRAM or PRAM, you may need to reconfigure your settings for speaker volume, screen resolution, startup disk selection, and time zone information. If issues persist, your Mac's logic board battery (not a portable Mac's rechargeable battery) may need to be replaced. The logic board battery helps retain NVRAM/PRAM settings when your computer is shut down. You can take your Mac to a Mac Genius or Apple Authorized Service Provider to replace the battery on the logic board.

Nov 5, 2015 9:23 PM in response to Sapote

A-A-A-A-A-AHHH!!!!! I have exactly the same problem, with the 3rd progress bar stalling (and then stopping) at about the halfway point. I run that data cable through an old USB (2) hub. That was my prime suspect. Now I don't know.


I need to get some sleep now. I'll be back in about 8 - 10 hours.



APC Back-UPS BE750G


iMac (Retina 5K, 27-inch, Late 2014), OS X El Capitan (10.11.1), 24 GB Memory

Nov 5, 2015 11:12 PM in response to John Galt

Update:


Hangs in same place with Restart. Could not get past #3 "Before Resetting SMC".


Shut Down and tried resetting SMC (I basically performed this when I first unplugged/plugged the iMac into the UPS). Regardless, it still hangs at start up screen.


Did not want to do NVRAM Reset.


Guess I'll be returning it... unless there's something else to try.

Nov 6, 2015 9:56 AM in response to Sapote

Update:


Heard back from APC/Schnieder Tech Support. Here's what they had to say;


I understand that your system hangs while powering on. I apologize for the inconvenience caused.


I would suggest you to configure the "native Mac shutdown" present in the Mac itself in order to have a graceful operation of your system.


Please follow the below link to refer the document to know how to configure "Native shutdown" for your Mac OS.


Link : http://www.schneider-electric.us/sites/us/en/support/faq/faq_main.page?page=cont ent&country=US&lang=en&id=FA159690


Please connect USB cable while configuring native shutdown.


Looking forward to hear from you!


If you have any further questions, please do not hesitate to contact me by responding to this incident. It would be my pleasure to ensure that your issue is quickly resolved!


Solutions to most common customer problems can be found in our APC Knowledge Base which can be found at:

http://www.apc.com/support/answers.cfm


Thank you for choosing Schneider Electric!


Their setup instructions support OS X 10.5 < and 10.6 >


Basically, they want you to make these settings adjustments (picture below). I've already tried a combination of Shutdown Options settings w/o success, including theirs. Report your experience.


User uploaded file

Nov 6, 2015 10:13 AM in response to Russ R.

I have the same UPS as do you (Back-UPS 750). However, I only have "Shut down computer when

the UPS level is below:" and have it set for roughly 5%.


I do see some differences. my FW is 841.13 and my USB FW is 13, which seems odd if as you say you just got

this as mine is quite old (years), but seems to have later firmware.


I am not having any issues. However, my UPS USB is plugged into a port on my

Thunderbolt Display which is attached to my late 2013 27" iMac. Wanted the USB3 ports

on the iMac available for high speed so connected it to the TB display since it is USB2.

That may or may not matter.

Nov 6, 2015 5:50 PM in response to Sapote

POSSIBLE SOLUTION!


When in doubt... turn off/disconnect everything. It's been working for me so far after multiple Restarts/Shut Downs.


Here's what I did:


  • Shut Down Mac and unplug from APC UPS.
  • Power Off APC UPS and unplug from wall outlet.
  • Disconnect USB cable.
    • Not that it probably matters at this point, but that's what I did.
    • Also, keep in mind that I had set up UPS Prefs and also performed the above "Before Resetting/Resetting SMC" instructions, but the latter did not help.
  • Wait 15-30 secs.
  • Connect USB cable between Mac and APC UPS.
  • Plug in APC UPS.

    I can't recall if I turned on power here or after next step - sorry.

  • Plug in Mac to APC UPS.
  • Power On APC UPS.
  • Power On Mac.


Hopefully it'll startup like normal now and bring up the login screen.

Jan 6, 2016 7:30 AM in response to Sapote

Hi. I've been having this same problem. It took me a long time to find this thread.


I also have a 27" iMac. However, I have a Cyberpower CP1000PFCLCD UPS.


I get the same hanging, at the same place, but only once in a while. Resolves after unplugging the UPS cable

from the iMac. I think the issue is not the UPS (either APC or Cyberpower) but 10.11.2.

They rewrote the USB stack and I think they haven't ironed out all the bugs yet.

I originally thought it was my usb hub, but even plugged in directly to my iMac it does this.


I tried all the other stuff (reset PRAM/NVRAM/SMC, delete energy save preferences, unplug everything).

I've filed a bug report with Apple. Hopefully resolves in 10.11.3.

Currently I'm using the UPS with the iMac plugged into it but without the USB cable.

Jan 17, 2016 10:26 AM in response to DrDuuude!

I'll just pile on here and note that I have had the same boot failure issue mentioned here since I updated to El Capitan. When restarting or starting from a power off state, the boot process (often - not always) freezes about half-way through the process (the progress bar stops about half-way through). Safe Boot doesn't work either. This issue has affected both my iMac systems - an iMac27 Retina (late 2014) and a four month old iMac 21.5. Both systems are running off APC battery backup systems, and both systems had the APC USB monitoring cables connected (the control panel showed the battery options). I discovered that I could consistently get my system to boot by powering off and disconnecting the external USB drives that I had connected - then the system would boot just fine. After it was running, I could reconnect the USB external drives and they mounted just fine and worked just fine. The external drives passed all the Disk Utility and WD Drive Utility tests.


Note: the systems sleep and recover from sleep without any problems at all.


On the MacInTouch forum, one poster suggested disconnecting the USB monitoring connection. I have done so, and my system seems to be back to normal. The control panel options for battery power no longer appear (the systems don't know they are running off a battery). This loss of functionality may be critical for some users, but not for me.


I believe this is an OS X issue. I think that if the USB monitoring connection is present, the OS is locking down the USB connections - and gets in a loop waiting for the external drives to mount - but that fails because a USB connection can't be established. Anyway, that is my guess. Note this has nothing to do with the apcupsd software - which is not compatible with El Capitan anyway.


Any other users with the boot failures should just try disconnecting the USB monitoring connection and see if that solves their problem. Perhaps Apple will fix this in an update, but it will be next to impossible to figure out if that happens, beyond repeated testing after every OS X point update, which will be a hassle.


David

APC Back-UPS USB Connection is Causing OS X to Hang at Startup...

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