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.

View in context

152 replies

Loner T

Level 9

59,536 points

Nov 12, 2017 2:26 PM in response to amytom12

Try

cd ~/Desktop

amytom12 Author

Level 1

12 points

Nov 12, 2017 2:29 PM in response to Loner T

Last login: Sun Nov 12 17:28:12 on ttys002

iMac:~ XXXXXXX$ cd ~/Desktop

iMac:Desktop XXXXXXX$

Loner T

Level 9

59,536 points

Nov 12, 2017 2:35 PM in response to amytom12

Also see Re: Installing Windows 8.1 doesn't work (Boot Camp says it needs an ISO image of Windows 8 or later) as an example.

amytom12 Author

Level 1

12 points

Nov 12, 2017 2:41 PM in response to Loner T

So if it's corrupted, do I have to reinstall a new ISO file and burn that new one to a new DVD?

Loner T

Level 9

59,536 points

Nov 12, 2017 3:04 PM in response to amytom12

The only method to know of corruption is to see what the MD5sum is. Do you see the ISO file in the directory? If yes, run both the commands and post the output.

amytom12 Author

Level 1

12 points

Nov 12, 2017 3:55 PM in response to Loner T

Nope, with or without the "ls -lg" part in it, there is still no string of code.

Loner T

Level 9

59,536 points

Nov 12, 2017 4:01 PM in response to amytom12

The ls -lg command is a directory listing. It does not produce a MD5. it should show the size of the file and one of your outputs does have it in this Today+520.png image.

amytom12 Author

Level 1

12 points

Nov 12, 2017 4:27 PM in response to Loner T

I'm still getting no string of code.

amytom12 Author

Level 1

12 points

Nov 12, 2017 5:04 PM in response to Loner T

Okay, will do! I'll tell you the results afterward.

amytom12 Author

Level 1

12 points

Nov 13, 2017 12:37 PM in response to Loner T

Hello! I just did the NVRAM and SMC reset and I inserted my DVD back in and opened BCA. I selected "Install Windows 7 or 8" and clicked on Continue. Same error as before.

amytom12 Author

Level 1

12 points

Nov 13, 2017 3:11 PM in response to Loner T

I don't know. Do you have the default file so I can just swap the old one out with the new one? I have X code too.

Loner T

Level 9

59,536 points

Nov 13, 2017 3:13 PM in response to amytom12

You will need to find the file from your local backup. I do not have one for a 2011 Mac.

amytom12 Author

Level 1

12 points

Nov 13, 2017 3:14 PM in response to Loner T

Hmm. I don't back up my Mac. SO I don't think there will be a backed up file.

amytom12 Author

Level 1

12 points

Nov 13, 2017 3:19 PM in response to Loner T

Ok, I don't want to reinstall macOS. But please give it a try looking for the file. Take your time, I'll be looking online for it too.

amytom12 Author

Level 1

12 points

Nov 13, 2017 3:26 PM in response to Loner T

Oh, wait, nevermind! I found a backup of the file I made. I'm now going to replace the edited file with the unedited one.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

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