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Hi everyone. I’ve just replaced the GPU card due to the AMD chip failure in this iMac series. Unfortunately I get no audio at all on this machine (no internal speaker available in OS-X ) nor microphone. I think that I forgot or failed to attach everything correctly, but… what? Thanks
It sounds like you swapped one of the speaker lines with the microphone line. All three look alike and of course all are located next to each other on the logic board. Review Steps 21 & 22 in this guide Installing iMac Intel 27" EMC 2429 Dual Drive Kit (HDD or SSD). One way to discriminate which line is what is to use a simple tone generator used to trace wiring. The speaker will respond and the microphone won’t Tone Generator and Probe Kit. Use a small sewing needle to pierce the wires insulation to then clip the hot lead of the toner.
