I've never baked a PS3, I've done computer motherboards and videocards. Usually I do 400° for 8 minutes, with aluminum foil balls on the corners. Allow plenty of time to cool as components can fall off when solder is melted.
For PS3s, it seems more care needs to be taken to insulate more fragile components like liquid capacitors.
Please refer to the following two resources for a more indepth picture guide:
http://www.ps3hax.net/showthread.php?t=30305
http://www.instructables.com/id/How-...an-oven/#step1