AW2521HF, fell down, damaged, repair?

The answer is almost certainly no -- it's not repairable.  Dell doesn't repair monitors. If they fail, they're replaced. But not for a fall, that is not part of the Dell monitor warranty. And very few if any repair shops will undertake a monitor repair.  Beyond the unavailability of screens, monitors are generally not designed to be disassembled for repair purposes - it's very common for screens to be fixed in place with adhesive.  Further, the screen is a majority of the cost of the monitor -- it's not an economic proposition to repair these, even if parts are available.

The Dell warranty won't cover the monitor. You have to use accidental damage coverage though your homeowner's or renter's insurance might, depending on the deductible you have.