回答“Replacement 120gb HDD not recognized in MacBook Air A1237”Hi, do you mean the disk utility that runs from the remote install program on another Mac or the installation program for Mac OS X? My new hard drive was not recognized when I wanted to install Mac OS X. There was no destination HD shown. Then I went to the disk utility program (under installer) and there it was. It was unformatted, so I formatted it as Mac OS extended (journaled). After that the installation program recognized it and I could chose it as destination volume.
回答“no sound on MBA”replace the audio cable. You can find the part and the instructions here on ifixit. I had the same problem. No sound, no speaker icons etc. Replaced the cable and now it is talking again. Good luck!