While I was working in a computer repair shop that supported both PCs and Macs, we would often run into systems that for one reason or another would not be covered by warranty. In the case of PCs, parts were almost always easy to come by. But for Macs, it was hard to get parts from anywhere but Apple. Enter (then) Pre-Owned Electronics. They did one thing and did it well, they provided quality repaired/refurbished Apple parts.
These days, they provide mail-in repair service for Apple and PC branded laptops. They have also recently added retail sales to their line-up.
Their support people are pleasant to talk with on the phone (or email) and are quick to respond.
If you need service, you should consider Blue Raven Technology, Inc.