There are two Boards:
The first one has
Chips with the name "Sony 501 0C 185", "Sony 502 0J 043", "Sony 504 1B 002 504-3", "Sony 509 01 017 509-00", "Sony 501A00 0A-1" and more.
It has two numbers: 21569 and 1-581-258-12
It also has the letter "B" next to the first number
The second Board has two (what I think is ceramic) ICs with the text "Sony 706 1G" and the other IC has "Sony 704 1G"
This board also has two numbers: "57850" and "1-581-255-12
It also has the letter "A" next to the "Sony Corp" text
Do feel free to ask for more info if you need more info to identify what the boards are and what they do.