First, to help diagnose your issue, you really need to provide more info. Was the machine printing perfectly before this happened? Had you done any maintenance or changed any parts prior to this? Did ANYTHING change before this occured?
EO74 CR2 usually means something obstructed the carriage and caused the machine to shut down;
1. Did you see if the printer possibly hit the edge of the media you were printing? What happened to cause the error?
2. Check your release plunger to make sure the bracket isn't bent - this is pretty common
3. Manually run the carriage back and forth the whole length of the rails, make sure there is no excess friction or "rubbing" that occurs
4. Can't recall if this could also mean an issue with the CR encoder strip - get a flashlight and make sure there is no ink/smudges/fingerprints on the strip and gently glean with a damp swab with a little alcohol.
As far as your printer not printing at all, you need to determine if the nozzles have somehow dried up, or there is an electrical issue with the head itself.
Do a head soak using a piece of coffee filter, with the carriage removed from the cap top, cut a piece of filter just slightly larger than the cap top and place on top of the cap top. Soak it good with solvent, then park the head on top of the captop to soak the nozzles. Let it sit for roughly 15-20 minutes, then remove the coffee filter and run a head clean. If you start getting nozzles back, repeat as necessary to get more nozzles back. If nothing prints at all, then you may have an electrical issue with a bad head cable or worst case, some kind of board issue.
Report back with more details, just too many variables to blindly try to diagnose this...