My Epson L3250 shows full black ink, but prints grey. What could be the problem?

This often indicates partial clogging of the print head nozzles. While the ink level is full, the ink isn't flowing freely. Try running a print head cleaning cycle (not power flush, a standard cleaning). Repeat this 2-3 times, allowing the printer to rest between cycles. If the grey persists, a power flush might be necessary.