Putting It Back Together
Remove the clip from the NOR/NAND. Unplug the Teensy++ 2.0/FlashcatUSB from your computer and detach any power cables. Desolder Tristate if you’re downgrading a NOR.
Make sure to clean off and replace the thermal paste on the heatsink, GPU, and CPU. Use isopropyl alcohol and paper towels and q-tips. You want to clean as much off as you can and to clean any off that gets on the motherboard.
As far as new thermal paste goes I recommend Artic Silver 5 or Artic Silver Ceramique 2. But many other kinds work just as well.
Now just follow the iFixit guide in reverse to put your PS3 back together!
Once it’s back together you should be able to turn it on and it should work like normal. But you’re not done yet.
If you patched to CFW and the CFW is higher then your original firmware it’ll boot to a black screen or just turn off after 5 seconds, that’s normal.