Did you ever try to download a user’s manual for an electronic product that you own but the manufacturer does no longer offer it on their site? There is hope: Try a search on Amazon.com. It hosts PDF manuals of thousands of electronic products including those of items that have either been discontinued or are no longer available for sale on Amazon.com.
Go to Google and type the following query. Replace the word PRODUCT with actual name of your product as in above screenshot.
PRODUCT filetype:pdf site:ssl-images-amazon.com OR site:images-amazon.com
Read the full post over on labnol.org: Find PDF Manuals for your Electronics using Amazon