Originally Posted by
Mungo64
Hi,
have now spent several hours to install the correct audio drivers on my iMac 27'' for Win7 64Bit (late 2009 i bought it probably July 2010) and all suggestions failed, including the ones above.
The problem was that Win7 always installs the default microsoft driverss, but they work only partly. The main problem is, that no sound ccomes out of the build in loudspeaker. There is actually audio when you connect a speaker or headphone to the mini-jack output. The output is also emitting a red light, via default drivers, which is not correct. It seems that it switched to the optical digital out.
Here is my solution to install the 'correct' drivers !
The iMac has actually two sounddevices. They appear as two individual devices in the device manager.
1. Device
The first one is not the one responsible for the normal audio. It has something to do with HDMI audio.
I have downloaded the 64-Bit Win7 drivers from the Realtek site.
EXE file. In my case the driver was not installed, but some necessray files where copied to C:\Program Files(x86)\Realtek\Audio\Drivers\HDMI\Vista64
In the device manager click: Update Driver->Manually Search on the Computer: Point to the above directory and click next.
The correct driver is installed and display himself as 'ATI HDMI Audio', which is funny when installing a driver from Realtek.
2. It seems that the 2.nd Sound-Chip is from Cirrus and has the name: CS4207. Go to the cirrus website and search for 'CS4207 Win7 driver'. Follow the link to the first entry in the result list. Goto the resources section: Under Tools and Software download the CS4207 Win7 driver.
It is a zip file. Just unzip it to a folder.
Now in the device manager update the driver for the second audio device: Point to the folder, where you have unzipped the Cirrus driver: Press next and install it.
This should work and after installion your iMac suddenly has sound on the speakers. The driver display as 'Cirrus Logic CS4206A (AB81).
Good Luck
Mungo
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