Have you looked at the ink lines to verify there is ink in them?
When you do the TEST PRINT, does the print head move out from the parked position and go through the motions as if it was to print the test print, if so and nothing is printed then I would assume the print head is NOT receiving the command to fire, so it is most likely an electronic issue, bad print head cable, or board (IMHO).
Any storms or lightning in your area (power surges) when this happened?
I use a large UPS for my printer, it helps to filter out power surges that can cause havoc to electrical components.