Plugged the system in, and the system powers on briefly then displays a blinking red light. I powered it down and began opening the system.
I removed a few small pieces of the case that were broken inside of the system. The top lid with the PS3 logo was also broken, and just slid right off.
I tested the system one more time before proceeding to pull the motherboard.
I pulled the motherboard and first examined it for any visible issues. Blown capacitors, scorched ICs or traces, etc...
Next, I cleaned the CPU and GPU and covered the surrounding areas in foil, as to shield the other components from the heat.
Using a heat gun, I heated the CPU and GPU for 3 minutes, keeping the gun moving in a swirling motion, and keeping the gun about 2-3 inches from the board. I let the board cool for an hour.
I reassembled the system and tested it after the reflow + new thermal paste, the result is the same: blinking red light
When I originally bought this system, it would display a solid yellow light. The reflow I performed at that time fixed the system, and I used it for about a year until selling it earlier this month.
I am going to do some research and see if there is anything else I can check. The PSU will probably be next...