Bought my O2 from the drop two months ago and have been having issues with the output jack recently. Decided to open it up to see if there was a simple fix and it looks like the output jack wasn't even soldered to the PCB.
http://imgur.com/skuJSTh
Ooph! If you need that soldered send it in and we can fix that for you. The 1st drop was with a new soldering technician and he made more than a few mistakes including not double checking the boards. We've brought him up to speed and so far I don't think we had any major problems with the most recent drop and shouldn't in the future.
Yup thats probably the issue that i have with mine. I already talked to tyler and getting my O2 shipped to get it repaired. I just dont want to yet im enjoying the sound atm.. xc lol
http://imgur.com/skuJSTh