Perhaps not exactly a fair comparison because I do this for a living, but I do all my own repairs. Almost all of my current daily use machines are systems that were previously faulty or damaged that I purchased, fixed up and returned to service. To share a few:
iMac (27-inch Mid 2011)
This machine's HDD fan failed and cooked the internal drive to death, and overheated the system in the process. As a result the thermal interface materials were also done as precaution.
- Replaced Hard Disk Drive
- Installed OWC HDD Sensor Kit
- Replaced Thermal Paste on CPU
- Replaced Thermal Paste and Pads on Graphics Card
- Repaired HDD Fan
- Replaced Optical Drive Temp Sensor
MacBook Pro (13-inch Early 2011)
This one was another liquid spill, requiring a replacement keyboard which is a complete strip down. It now looks almost immaculate inside and out.
MacBook Air (13-inch Early 2014)
This one had some corrosion inside it from a water spill. It's now corrosion-free and looks immaculate inside and out.
- Replaced Trackpad
- Replaced IPD Flex Cable
- Repaired Keyboard (cleaned key matrix, replaced two key lifters)
I make this somewhat of a hobby of mine, albeit one of waning interest. These days I mostly fix machines, keep what I want to use or have as a collectors item, and move on anything else to whoever needs it. I have about 10 completed machines in storage at the moment, a further 3 awaiting completion and a small storage of spare parts for all of them. There's also something nice about keeping a machine in service as opposed to sending it off to landfill.