When taking apart anything Apple, be very, very careful of the connectors. They are essentially land-mines, especially inside iMacs and phones.
Call Apple early in the process. If a few web searches lead nowhere, don't be ashamed. It's OK. Call Apple.
Save the case number they give you when you call them. If resolving the issue requires the dreaded trip to the Apple store with your fallen prized-possesion in tow, having the case number makes the whole experience a little less shameful.
Here's my iMac saga:
A few months ago, the headphone port died. Bummer. I use it to feed a pair of near-field speakers. I did all the hocus-pocus I found on the internet, and finally decided to call Apple. After a two minute session, they declared the logic board needed to be replaced. The good news.... it was still under warranty. The bad news.... I had to lug this huge-screen beast to the Apple store in the Mall. I saved the box, and I have a little fold up dolly, so it wasn't too terrible.
Well, from the time I called to the time I brought it in, the warranty expired. However, I had the case number from the follow-up e-mail Apple sent after the call. The store decreed they would honor the warranty! Whew. $750 saved.
So after waiting a week, having a paranoia attack and changing all my passwords, and not doing any video work, I was informed from on-high my beloved machine was healed.
Off to the Apple store I went, battling crowds of , well, people, inside the store, and finally getting up to the genius bar (reference Big Bang Theory) I at last loaded up my machine with the help of a friendly and attractive genius-ette.
Racing home to set it up, I was hugely disappointed to discover the headphone audio, while now showing up in the settings, was intermittent at best, and the plug would not seat properly.
Take it back? NO WAY. How hard can it be to replace the connector?
After watching a few videos and procuring my GoPro suction cup mount, I proceeded to enter the sacred temple. I must say, it is unbelievably beautiful inside, and very cleverly and thoughtfully built.
I was delighted to discover the connector, at the end of a nice flat cable, was just not properly seated into its little clip mechanism. After examining and admiring the roller-ball contact points, and the optical interface (that's right an optical interface like a spdif) inside the mini-plug, I snapped it in place, tested it out for a good mechanical seat, and then proceeded to re-assemble my machine.
One of the little connectors, a flat cable with a tiny, tiny, tiny 30-pin connector would not plug in to the logic board. Upon examination, there is a lock for the connector, and when I removed the LCD display I must have bent the cable-end of the connector. It was ruined. Looked like a prize-fighter's teeth on close inspection with a glass. Crap!
Back to the internet, and after a little searching, I found a replacement cable, and several stories of woe from people who did the same thing, and worse, pulled the board-side connector off. Yikes! At least I didn't feel so bad now.
So, after waiting the weekend, my cable arrived today. I was terrified that I may have contaminated the board-side connector. I waited awhile until things were nice and calm around here, then I tackled the cable replacement.
LO and BEHOLD! It worked! Board-side connector must be OK. Everything went nicely into place, and it was time to button up my machine and exit the sacred temple, careful not to leave anything behind.
So now, I'm typing happily away on my iMac, listening to iTunes through my Yamaha near-fields, and looking forward to getting some video finishing done in the morning.