For a long time, iPhone 5 users have been complaining that the Power button is not working. Finally Apple has confirmed the "iPhone 5 Sleep/Wake Button Replacement Program" that offers replacement or fix to this issue starting on April 25 in the United States and the 2nd of May in other countries.
Note: If you have problems with iPhone 5 battery instead of the power button, check to see how to fix iPhone battery issue.
As long as you are eligible (i.e. have a qualified serial number), Apple will replace the troubled component for free, even if your iPhone 5 is out of warranty. You can follow the tips below to find out if your power button can be replaced for free by Apple:
If your serial number shows eligibility, you will get a message saying: The iPhone 5 serial number you entered is eligible for this program. Please follow the instructions below to have your sleep/wake button replaced.
Then you will have to take your iPhone 5 to Apple Store for repair or mail-in the iPhone 5 to Apple through a postage-paid service they offer and wait for about a week to get it fixed. Those who have already paid for the replace of iPhone 5 power buttons can now apply for a refund.
If you don't want to settle with this option, you can also enjoy a $350 trade-in credit towards a new device, which is offered by the Apple Store in the United States. The trade-in requires that other part of your iPhone 5 is in good condition and works fine as well.
Worry about all the data on your old iPhone 5 after you get a new iPhone through the trade-in? Totally no need as you can transfer data from old iPhone to new iPhone easily.