no airport or audio device installed with replacement left io board

A few weeks ago I was just working on my MacBook Pro (Model A1226) and suddenly my screen turned black. The screen was not off but the backlight of the screen did not work anymore. When I connected my macbook to an external monitor I noticed that my macbook's airport, audio jacks and speakers and the left usb port did not work anymore.

After some searching on the internet I did not found a similar problem, but i deduced that my left i/o board was broken. I ordered a replacement part and installed it with the manual on this site.

Everything is correctly installed I checked three times!

After the installation, i started up my macbook and the screen worked, so I thought that it was fixed, but the airport card and sound outputs does not work. The left usb on the other hand now does work. I rechecked the connection to those hardware devices and they are well connected.

The error that I see, when I click on the airport icon in the top bar, is: "no airport card installed". The airport card also does not appear in the system profile utility.

The errors with the audio are: I am unable to adjust my volume and in system preferences, under the audio section, there is a message saying "no output devices found", "no input devices found"

Also in the system profile utility, under the audio section there is only two lines of text saying "Intel High Definition Audio" and "Audiocode: 0"

I do have sound when I connect an usb headphone to my laptop. But that's the only case.

Does anyone know what this errors could be?

Could it be that my replacement part is broken (I ordered it from the ifixit website)?