HP 2512: not feeding paper, rollers aren't moving

My printer is no longer feeding paper when a single sheet is loaded or a stack. It makes a sound like it’s trying to feed the paper, but when I shine a light down into the printer, I do not see that the light gray rollers are rotating when the printer rests them against the paper.

I saw a similar issue (and fix involving epoxy) for a Deskjet that has a horizontal tray, but mine has a vertical tray so I imagine the fix will be a bit different if there is one. Thanks to anyone who has a solution here.