1st gen Macbook Air problem, black screen with one beep continuously at start up, posted here 2 weeks ago: http://forums.macrumors.com/showthread.php?t=1499858 After doing some research I was ready to call it a loss, since the value of machine just doesn't justify the cost of logic board replacement. Now, I currently live in Shanghai, I decided to visit one of the many repair shops anyway, just to give it a shot, no charge if not fixable, nothing to lose. Guess what? 1 day, 600RMB (little under $100 USD), it came back to me working again flawlessly. They simply just removed bad memory and soldered good ones to the board. As a bonus, even my airport non-existence problem is fixed too during the repair. They also guarantee their work for 6 months. So, if anyone has the same problem, instead of giving up or paying Apple to change the logic board, might well just give it a try at those independent shops, soldering memory isn't a DIY job, but can't be that difficult, afterall thousands of workers at FoxConn factory are doing it.