Users have reported several iPhones 5 models with a broken sleep/wake button, something which Apple are finally addressing. "Apple have determined that the sleep/wake button mechanism on a small percentage of iPhone 5 models may stop working or work intermittently," said the company on the official Apple page. "iPhone 5 models manufactured through March 2013 may be affected by this issue. Apple will replace the sleep/wake button mechanism, free of charge, on iPhone 5 models that exhibit this issue and have a qualifying serial serial number."
All you have to do is head to the program page and input your serial number there. Following that, you can either send your iPhone for repairs by mail or go to your closest Apple store. The latter option will get you a replacement 16GB iPhone while yours is in the shop.
While the program has started in the U.S. and Canada, international iPhone 5 users will have to wait till May 2.