Question Epson ET-4700 paper scan loader failed - FIXED but more question

[jnash12]

Not entirely sure why this fixed it, but single or multiple pages in the scan feeder stopped working. Careful review, there is a white plastic stop that sets you up to ensure your paper is positioned correctly to begin scanning. However, the paper is yet to be over the optical lens to detect paper present until the paper is at least grabbed be the roller just a bit at the beginning of each scan.. My rollers are clean and nothing apparently broken in that mechanism.
So, installing a piece of black PVC tape over the optical sensor makes the scanner believe paper is (always) present and now it works.
Any comments on the root cause so I can remove the black tape over the optical sensor?

 

[Ralston18]

Is the optical sensor/lens out of alignment or some adjustment?

In other words if the optical sensor is not "pointing" at the paper to detect that paper is present then the sensor sees "no paper".

The black tape is simply fooling the sensor into thinking that the sensor is seeing paper.