Not that I know lot about the electronics industry, but I'd suspect that the choice of components (i.e. their Bill-of-Materials) of products from large multi-national consumer-electronics / imaging manufacturers are typically kept secret, including who does the assembling/sourcing (EMS) for them etc., because that in itself gives them a strategic advantage over their competitor and new entrants. However again, from the reading / listening I've done so far, usually this doesn't remain a secret for long, as enthusiasts (or hackers) eventually perform a detailed "tear-down", and reveal pretty-much everything that's in there. Sometimes, some manufacturers (I've seen this in some of the teardown of smaller devices I've done), try to obscure components by etching the surface, or put stickers that are very hard to remove etc. Finally, some common, high-volume consumer electronics (mobile-phones for instance) have their detailed schematics/BOM's made available by manufacturers to third-party service agencies, especially after their end of active-sales. This, I found to be true for many mobile-phones. AFAIK (and I don't know much), there is no single official source of such information, other than the manufacturer themselves.