Take Apart PS3
You’ll need the motherboard without anything attached to it. You don’t need to take the fan out of the heatsink assembly. I recommend using something like an ice cube tray to put screws in. Use a different cube for each layer you take apart. One cube for the outside screws, one cube for the screws that go on the top side of the motherboard, etc…
Find The Chip
Now we need to find the NOR or NAND on the motherboard. Since there are so many different motherboard revisions there are a lot of places the NAND or NOR could be located.
Here is a list of all the different motherboard revisions on psdevwiki.com.
I’ve taken pictures of the downgradable motherboards from there, and annotated them with their NAND/NOR locations.
COK - 001
NORs have only one NOR.
NANDs have two NANDs. Both need to be dumped and then flashed to again. There’s NAND0/LOW and NAND1/HIGH, you can see which is which in the pictures above.