All lights flashing is called a "Fatal Error" This is PER EPSON. I use to see this weekly from people that had a paper jam. When you un-jam the paper, I'm guessing you pulled it out the way it went in. What happens when you do this, is you actually pull the paper sensor out of it's cradle. Therefore it sees that the sensor is not functioning properly, giving you a fatal error. If I remember correctly it is quite a pain to get the sensor back where it belongs. IF you are mechanical and want to give it a try, just be careful and remember where everything goes. Write it down or something.
Look into the slot where you feed the paper in. you may be able to see the sensor with a flashlight. It's impossible for me to walk you through this, but if you want to try, now you know what to look for.
If this was an inexpensive printer. ($50-$60) Personally, I would get another printer instead of trying to fix it. From a service point of view, the labor to fix this if you brought it into my shop would be more than a new printer. Providing it was a cheaper model.