I used that manualsonline.com site 4 times to no avail. I tried to get a manual for a HP Photosmart Printer 240, Photosmart 1500, Photosmart C4200. Each time the response said "Wev'e got hundreds of thousands ofmanuals here at manual on line, but it looks like we don't currently have the exact manual your looking for". This to me feels like they wanted to direct us to other commercial web site. I somehow got redirected to Robotdriver.com wanting me to spend $29.95 to update my driver base.
These are not newly manufactored printers and if any manuals that Manualsonline.com would provide a copy to be downloaded, not their only copy.