Print feeder not working

Common CMYK inkjets like this aren't built for longevity and use parts that wear within a few years, and to make matters worse you can't easily replace them a lot of the time BY DESIGN. They make their money on ink at the expense of reliability and SW support on a lot of these. They only added the drivers for many of these a few years ago because they lasted too long and couldn't hide the spiteful lack of support much longer; I had a NX415 in high school as a scanner, Epson dropped it when Rosetta 1 died because the 88/69/68 was well and truly cloned and brought it back as a "legacy" product 10+ years since getting rid of mine. Look for yourself. The renewed SW support isn't a goodwill gesture; it's meant to hide the ink DRM behind smoke and mirrors. They make money on the ink.
I was in a death loop at the time; take advantage of the open 3rd party ink market because Epson gave up and buy another old Mac to run SL on to keep the NX415 for a while or scrap it (it ran out of ink, the prior owner noped out of it) and if I ever needed it, I need that Mac; or junk it. They wanted to get them out of circulation and took mine out because inkjet does not store well and if you let them sit too long you lose the head due to a permanent clog with Epson and won with mine.

It's a generational issue with these old Epsons. One of the things they did/do a LOT is stop supporting these with new drivers and HW repairs within a few years; usually once the aftermarket has dealt with their nonsense like cloned chips, wetness sensors, or firmware bombing. The "drop OS support and limit HW repair" stunt isn't as openly done these days because the scam is well known; they silently admit defeat on the firmware bombing side of things when it's well and truly opened up and stop trying. Once it's open it's open but they stop selling all of the old printers and block the 3rd party carts with the next generation of printer firmware. The old scam was even more evil: The 88/69/68-2010 black cart printers had a wetness sensor in the back that talked to the external chip and if you got it under 25%, the refills were spotty and not likely to work out OR if it went down well below you permanently nerfed the chip and had to replace it. Usually, it killed the chip at 25% to be extra sure to block refills from being viable.

This isn't even new: They also did it with pre-2000s chipless printers which could be "reset" with a piece of Scotch tape and replaced with chipped printers. However, the chips were a joke and reverse-engineered in no time. As soon as the casual market moved to newer less insecure models they stopped supporting these once the ink sales went to nearly nothing; do you see a pattern with the old Epsons yet? I CAN STILL REFILL THESE ALL DAY LONG AND BUY THE PROGRAMMERS if I find a survivor, but I can't use it on a modern computer! I need an old iBook or something.

This wetness sensor stuff stopped in 2010 with the "black cart" era (as I call it) due to the EU (thank goodness!) but the firmware was globally DRM-bombed as a countermeasure against the EU. These have a unique ID per chip with the 25% RO lockout to prevent reuse too; as well as blocking 3rd party carts with false errors and firmware bombs disguised as "security updates". The new hack with the new firmware bombed Epsons is to bypass the BS with chipless FW which requires hackable firmware so you never want to update it (which is a bad idea anyway as "security update" means breaking old 3rd party ink sets).

Unless you get lucky and find a donor with a low PC, you will not find the parts easily. You might be able to try a cleaning page or rubber rejuvenator but these patch the problem.