Hi S Lawrence,
Welcome to Apple Support Communities.
If I understand correctly, your MagSafe 2 Adapter is no longer working after plugging it into the wall socket and hearing popping sound. It sounds like your MacBook Air accessory could need service, try taking it in for an evaluation as suggested in the article below.
Apple Portables: Troubleshooting MagSafe adapters - Apple Support
Whether or not your product is in or out of warranty, you can take your adapter to an Apple Authorized Service Provider or Apple Retail Store for evaluation and replacement if necessary. Pending the results of the evaluation, you may or may not be eligible for a replacement adapter free of charge. Signs of accidental damage would negate any coverage. Be sure to bring in the computer used with the adapter; it is required to process potential adapter replacements.
Also, this webpage provides a lot of great information about the available service options for your Apple devices:
Apple - Support - Service Answer Center
So long.