MacMini 4,1 sound scrambled after upgrade to Sierra

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Level 1

8 points

MacMini 4,1 sound scrambled after upgrade to Sierra

I have a MacMini 4,2 (Mid 2010). It was running ElCapitan and I never had any issues with it. I just upgraded macOS today to Sierra and now all sound output is scrambled. I checked and tried everything in System Preferences and the Audio MIDI Setup, even reset NVRAM, PRAM and SMC but no changes. This system was working perfectly before the upgrade, anyone has an idea what else I could try to get my sound output back to normal? Since I use this MacMini as media server for music and movies I'm extremely frustrated with the sound issue since it renders the Mac unusable 😟

Mac mini, macOS Sierra (10.12)

Posted on Sep 30, 2016 4:46 PM

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Answer 1

lllaass

Level 10

210,519 points

Oct 1, 2016 1:13 AM in response to OliCalgary

What do you mean by scrambled?

Are you using special output software? Midi?

What sound output are you using? USB? Headphone jack?

Try a different output.

Do you have a problem when booting with Shift key depressed? That is Safe mode?

Do you have problem if you log in as a different user?

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Answer 2

OliCalgary Author

Level 1

8 points

Oct 1, 2016 7:16 AM in response to lllaass

Thanks for your reply. By scrambled I mean it sounds like underwater mixed with static/noise. No special software is used. All sound outputs (iTunes Music, Movies, System sounds...) are like that. Output used is the headphone jack with an optical cable to the speakers. If I plug in a headset there is no sound at all, same for the internal speaker, although the volume control is present. I'll try safe mode today. Same for all users. I read that many people have sound problems after upgrading to Sierra. Some people posted it has to do with HDMI, so I tried to unplug the HDMI cable while playing iTunes music and sure enough the sound goes back to normal instantly. Plug HDMI back in and sound is scrambled again 😟 Unfortunately I can only connect the Mac to the TV via HDMI... If I can't find a fix I have do downgrade to ElCapitan again until Apple comes out with a fix 😟

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Answer 3

lllaass

Level 10

210,519 points

Oct 1, 2016 7:25 AM in response to OliCalgary

I would try:

- Try resetting the SMC and NVRAM/PRAM

Intel-based Macs: Resetting the System Management Controller (SMC)

https://support.apple.com/en-us/HT201295

About NVRAM and PRAM

https://support.apple.com/en-us/HT204063

- Try starting in Safe Mode

OS X: What is Safe Boot, Safe Mode?

https://support.apple.com/en-us/HT201262

- Boot to Recovery and repair the startup disk

OS X: About OS X Recovery - Apple Support

https://support.apple.com/en-us/HT201314

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Answer 4

OliCalgary Author

Level 1

8 points

Oct 2, 2016 4:22 PM in response to lllaass

My research so far came up with a HDMI problem. If I disconnect HDMI from the Mac my sound is instantly ok again, plug the HDMI back in and it gets "scrambled" again 😟 This is with a regular HDMI cable from Mac to TV (and yes, I tried quite a few different HDMI cables to make sure its not the cable). Strangely, if I connect the Mac HDMI to a computer monitor with an Apple HDMI-to-DVI-adapter the problem doesn't occur. Seems like it only happens when I connect the Mac's HDMI to another HDMI on the TV or Receiver-Box... I tried Safe Boot Mode and resetting SMC and NVRAM/PRAM but no change...

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Answer 5

OliCalgary Author

Level 1

8 points

Oct 2, 2016 6:06 PM in response to OliCalgary

I played around with my problem for hours now and came over a "solution", at least temporary. I have the HDMI cable plugged into the MacMini and power it on. I select my user account and enter the password for unlocking the FileVault startup disk. After confirming the password I UNPLUG the HDMI cable and let the MacMini boot until its on the desktop. Then I plug the HDMI cable back in and for WHATEVER REASON the sound works like a charm. At the moment better than nothing I guess, since I don't reboot this MacMini a lot it's a workaround. But not really happy with it... Hope it gets fixed on a future Sierra update. Hmmm...

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Answer 6

Oct 12, 2016 6:36 AM in response to OliCalgary

Hello,

I also have a mac mini mid 2010 and have a sound issue. It is different to yours however, I have no sound at all from the inbuilt speakers, but when I connect my Bose speakers via bluetooth it works fine.

I have my monitor connected using HDMI cable and am wondering if that is the problem, trouble is if I disconnect I have no screen.... No idea what the fire vault thing is I am afraid or I would try that. As I can have sound I suppose I should wait for the next update and hope it gets fixed!!!

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Answer 7

Oct 12, 2016 6:35 AM in response to OliCalgary

Hello again,

I just played a song in iTunes using internal speakers ( no sound of course) and took out he HDMI cable, as I was pulling it out the sound come on but once pulled out the sound went off again. When I plugged the HDMI back in the same happened I had sound for a second as the plug was being pushed in then once fully in nothing... so .... The programming for the HDMI is definitely the cause of the problem.

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