Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
If the top feeder does not 'take up' paper, when a sheet to copy or fax, or a document is placed in it, that usually means either
A. that the top feeder assembly has become disconnected from the rest of the printer (less likely) or
B. that the sensor that tells when the sheet or document is placed in the top feeder, is fouled or dead or unplugged or otherwise defective. (Which is the more likely of the two cases.)
So I advise you to check the sensor in the top feeder when the paper is placed, and then check the cable to the rest of the printer as to whether it has obviously had strain placed on it, has been pulled, or perhaps even broken or cut through.
(If you would like more specific advice, please tell me the printer's maker and model # ***** age.)
I honestly confess that I do not know the exact location of the paper presence sensor in that model, nor can I find specifics about it.
As for opening it to examine it, here's how:
1. lift the scanner cover:
2. pull down the ADF mechanism as shown:
The paper sensor may be visible there, as a very small piece of plastic protruding into the path that paper would take when put into the ADF feeder.