Since it happened after "refilling" the cartridges I would suspect that may be the problem.  If you refill cartridges they may or may not work, you take your chance.  New Dell cartridges are probably the next step.

Does this thing REQUIRE DELL cartridges or are other brands available?

There may be "remanufactured" cartridges with various non-Dell brand names, but they are not "new" Dell cartridges.  They are the same as refilled cartridges, they may or may not work.