Level 1

12 points

No sound on 27 inch iMac Mid 2011 running Windows 8.1 on Botcamp

Hello! I just installed 8.1 on my Mac and everything went very well. Then only issue I found is the sound and the brightness. I try to turn down the brightness but nothing happens. The bar shows that it's going down but it isn't. The sound is also broken. When I try to turn up the sound, there is a circle with a cross with the volume icon. I tried many things to fix the sound issue. I tried downloading new drivers, updating drivers, etc. The brightness issue, I don't really care but it would be useful if we can fix it too. I talked to Microsoft about the sound problem and they said the only way to fix it is to get Windows 10. Unfortunately, my mid 2011 Mac does not support Windows 10 on boot camp. I'm in desperate need of the sound in windows so I need your help! Thanks!

Posted on Oct 15, 2017 8:28 PM

Top-ranking reply

Loner T

Level 9

59,536 points

Posted on Oct 16, 2017 5:46 PM

Does your built-in Optical drive function properly?

amytom12 wrote:

And oh, I forgot to mention. When I was installing Windows 8.1, I got a MBR table error and something about EFI's and GPT. I looked on YouTube and this guy said to go to terminal on my mac side and put some codes in. I don't know if this effects the sound.

Yes, it does. If you do not use the internal Optical drive and a DVD (or CD) to install Windows on your specific model and instead use a USB (or manually choose) EFI boot, the Audio devices are not exposed correctly. This is indicated by the current BIOS Mode being UEFI. On your specific 2011 model, it should be Legacy (or BIOS).

The only method to switch to BIOS mode, is to remove the current installation using Remove Windows from your Mac - Apple Support and then use a DVD in the Optical drive to install W8.1. The 'code' you were asked to input in Terminal removed the MBR, forcing a UEFI installation, and causing the Audio to malfunction.

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152 replies

Loner T

Level 9

59,536 points

Nov 15, 2017 2:45 PM in response to amytom12

SIP needs to be disabled for El Capitan and Sierra as well. These steps are executed in Terminal. Step 1 invokes GDisk. and the remaining commands are entered in the GDisk utility.

amytom12 Author

Level 1

12 points

Nov 15, 2017 3:18 PM in response to Loner T

Okay, I turned SIP off and it said that it was a success. I rebooted into my system again, now what do I do?

amytom12 Author

Level 1

12 points

Nov 15, 2017 3:23 PM in response to Loner T

Okay, also, as of now, should I have the Windows Partition made yet? Or do I have to do this first before I can make the partition?

Loner T

Level 9

59,536 points

Nov 15, 2017 3:24 PM in response to amytom12

You need the FAT32 partition first.

amytom12 Author

Level 1

12 points

Nov 15, 2017 3:54 PM in response to Loner T

I'm getting an error:

Loner T

Level 9

59,536 points

Nov 15, 2017 6:07 PM in response to amytom12

Can you run Disk Utility First Aid and then try to create a FAT Partition? Did you abort the previous FAT partition creation?

Loner T

Level 9

59,536 points

Nov 16, 2017 2:26 PM in response to amytom12

Can you try to run

sudo tmutil thinlocalsnapshots / 9999999999999999

and retry?

amytom12 Author

Level 1

12 points

Nov 16, 2017 2:29 PM in response to Loner T

Is this correct?:

sudo tmutil thinlocalsnapshots / 9999999999999999

Password:

thinlocalsnapshots: Unrecognized verb.

Loner T

Level 9

59,536 points

Nov 16, 2017 2:35 PM in response to amytom12

What is the macOS version on your Mac?

amytom12 Author

Level 1

12 points

Nov 16, 2017 2:44 PM in response to Loner T

macOS 10.12.6. I did that command and got an error. But it's a different one.

"MidiaKit reports partition (map) too small. If you recently grew your whole-disk, you should run whole-disk repair."

amytom12 Author

Level 1

12 points

Nov 30, 2017 2:25 PM in response to Loner T

Hello. I'm sorry for the inactivity. My GPU broke and it got repaired. The GPU broke on the day I did the partition but not during the partition. Do you think this had to do something with the GPU?

Loner T

Level 9

59,536 points

Nov 30, 2017 3:53 PM in response to amytom12

Very unlikely. iMac (27-inch, Mid 2011) - Technical Specifications has the AMD GPUs. Let us try and install Windows and see if we can address the Audio issue.

amytom12 Author

Level 1

12 points

Dec 1, 2017 12:58 PM in response to Loner T

Alright, I wiped my HD so I'll try to create a new partition.

amytom12 Author

Level 1

12 points

Dec 2, 2017 6:08 AM in response to Loner T

Loner T

Level 9

59,536 points

Dec 2, 2017 7:58 AM in response to amytom12

Are you able run BCA and click on Install and make it work, or do we need to bypass BCA with manual partitioning?

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No sound on 27 inch iMac Mid 2011 running Windows 8.1 on Botcamp