Document Feeder Didn't Recognize Paper as Loaded

[Hazelg]

I came across a discussion online that had already been archived, and various suggestions were made to fix  this problem. I was trying to go back to it by logging in but can't find it. I did not at all understand the advice about black and white rollers and their guilt in this matter. All I see is gray and black rubber looking rollers and white plastic grooved rollers at various places. So I could not follow any of those suggestions--a photo might have helped. But there were two suggestions that made a difference. One was to restart the printer, and the other was to unplug it for 60 seconds. I did both. And that appears to have resolved the issue where it pings when you add the paper to the document feeder, but the message is that no paper is loaded. Now, I was actually able to scan something. I do not know how long this will last, however. I also want to corroborate what several of the participants said about hp support. It's awful, and I never intend to buy another hp product. As it is, this printer won't print anymore, so I have only been using it for scanning and to a lesser extent faxing. I hope this helps.