Thank you for your reply! Some additional info, not sure how relevant. My MacBook Air had the OEM power supply attached at the time of the failure. The original battery was giving a service battery warning and was replaced by AppleCare 3 1/2 years ago. I started getting another service battery warning about two years ago, although I have not had problems with battery usage. The wireless stopped working about 1 1/2 years ago, so internet has been by using the USB/Ethernet adapter. I believe it was running OS 10.10.
The Air has been a secondary computer since buying an iMac shortly after the first battery failure. My closest Apple Store is 120 miles away, so a service road trip is not an option. I was mainly curious about what type of code the timed beep and sleep light flash might mean. Thanks for your reference. I assume either the processor or the graphics chip fried from age and/or heat. Realistically, it is probably time to move on to either a new MacBook or an iPad Pro with keyboard cover. Its just that I hate to give up on the Air without knowing. 🙂