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

amytom12 Author

Level 1

12 points

Nov 12, 2017 4:40 PM in response to Loner T

Oh wait, nevermind. It turns out that I just had to wait a few mins for the code to show up. This is what i got:

Last login: Sun Nov 12 19:18:36 on ttys002

iMac:~ XXXXXX$ openssl md5 /Users/XXXXXX/Desktop/Win8.1_English_x64.iso

MD5(/Users/XXXXXX/Desktop/Win8.1_English_x64.iso)= e0d4594e56c0545d379340e0db9519a5

iMac:~ XXXXXX$

Loner T

Level 9

59,536 points

Nov 13, 2017 3:17 PM in response to amytom12

The earliest I can look for one is this weekend. One option you have is to re-install macOS (the same version as your current internal disk version) and an external disk, and then copy the file to your internal disk.

Loner T

Level 9

59,536 points

Nov 14, 2017 12:56 PM in response to amytom12

amytom12 wrote:

So I just have to copy and paste "sudo codesign -fs - /Applications/Utilities/Boot\ Camp\ Assistant.app" into terminal and it should work? And what is "--deep"?

Instead try

sudo codesign --deep -fs - /Applications/Utilities/Boot\ Camp\ Assistant.app

It recurses through the directory structure. In Terminal you can type man codesign which will give you details of the command.

amytom12 Author

Level 1

12 points

Nov 14, 2017 1:15 PM in response to Loner T

Okay, this is what I got...

sudo codesign --deep -fs - /Applications/Utilities/Boot\ Camp\ Assistant.app

Password:

/Applications/Utilities/Boot Camp Assistant.app: replacing existing signature

/Applications/Utilities/Boot Camp Assistant.app: resource fork, Finder information, or similar detritus not allowed

Is that correct?

Loner T

Level 9

59,536 points

Nov 14, 2017 2:37 PM in response to amytom12

I think you code signed the existing Info.plist, not the original. You will first need to copy the original to it's current location.

sudo cp <OriginalFile> /Applications/Utilities/Boot\ Camp\ Assistant.app/Contents/Info.plist

and then run the 'codesign' command.

Loner T

Level 9

59,536 points

Nov 15, 2017 1:25 PM in response to amytom12

Excellent. Run Disk Utility and create a FAT32 partition of the size you want Windows to be. We will also need to manually create a MBR. Once the MBR is created, on this screen you will need to select the Windows icon.

As a test, if you select the Windows icon, does the Windows installer start?

amytom12 Author

Level 1

12 points

Nov 15, 2017 3:28 PM in response to Loner T

Okay, the partition is currently making. Meanwhile, I did those commands, and this is what I got this:

sudo gdisk /dev/disk0

Password:

GPT fdisk (gdisk) version 1.0.3

Warning: Devices opened with shared lock will not have their

partition table automatically reloaded!

Partition table scan:

MBR: protective

BSD: not present

APM: not present

GPT: present

Found valid GPT with protective MBR; using GPT.

Command (? for help): sudo gpt -vv -r show /dev/disk0

You may need to edit /etc/fstab and/or your boot loader configuration!

Command (? for help): sudo fdisk /dev/disk0

You may need to edit /etc/fstab and/or your boot loader configuration!

Command (? for help):

amytom12 Author

Level 1

12 points

Nov 15, 2017 3:39 PM in response to Loner T

Ah, okay... So do I just do all of these steps in terminal after the partition is complete?

Sudo gdisk /dev/rdisk0
P (Print list of parts)
R (Recover)
O (print current Hybrid MBR)
H (chooses Hybrid)
Partitions numbers to be hybridized: 2 3 4
Y (Good for GRUB question)
N (part 2 boot flag)
N (part 3 boot flag)
Y (part 4 boot flag make NTFS bootable partition)
O (print current Hybrid MBR)
W (Write the new MBR)
Y (Yes! write the new MBR)
Reboot

After this is done, I just do "

sudo gpt -vv -r show /dev/disk0

sudo fdisk /dev/disk0"? Is this correct? Sorry for asking so many questions, I just want to make sure I'm correct and don't want to mess something up.

amytom12 Author

Level 1

12 points

Nov 16, 2017 1:02 PM in response to Loner T

I ran the first aid. Then I tried to create a FAT. But this time, I got a different error:

"Media reports not enough space on device for requested" If it's talking about how much storage I have, then it's wrong. I made the partition 210 GB when I still have 450 GB left. So roughly half goes to the Windows side and half goes to the macOS side.

amytom12 Author

Level 1

12 points

Dec 1, 2017 1:01 PM in response to Loner T

That's what I get when I choose MS-DOS (Fat). It says " This volume can not be resized"

This is what I get when I choose Mac OS Extended (Journaled). I don't get the " This volume can not be resized" message. Is this supposed to happen?

Loner T

Level 9

59,536 points

Dec 3, 2017 6:56 AM in response to amytom12

Even if you do not have important files and are willing to lose all data, the question is are you willing to spend time re-installing/re-building the iMac from scratch. The backups just help in a quicker erase/re-install.

amytom12 Author

Level 1

12 points

Oct 16, 2017 4:39 AM in response to Rudegar

Hello! Thanks for the reply! Could you please lease show me step by step on how to do the that? I'm not that tech savvy. Thanks!

amytom12 Author

Level 1

12 points

Oct 16, 2017 4:43 AM in response to Loner T

Sure, I'll check that's info when I get home today. The version of macOS I'm not sure but I know there is a 12 and a 6 in it and it's not high sierra. Thanks!

Loner T

Level 9

59,536 points

Oct 16, 2017 4:46 AM in response to amytom12

Stay away from High Sierra, if you can. I highly recommend backups on a regular basis.

amytom12 Author

Level 1

12 points

Oct 16, 2017 5:20 AM in response to Loner T

Yeah, I heard it's not that good. I'll be home in about 8 hours then I'll tell you the result from the msinfo32

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