The printer remembers that a job order was in progress, but that it was interrupted by an error (jammed paper, then no ink). However, it has not realized that the errors have been corrected, and thus the job is still pending (that's why the light's flashing). Try pressing the power button a couple of times and see if it continues to print. If not, click here for HP's troubleshooting guide to a flashing power light. If that doesn't work, click here for instructions on how to cancel the print job. By cancelling the job, the printer should return to a state of readiness, with the green light remaining solid. You can then send the print command again.
Hope this helps,
I was printing a letter, when a page got stuck in my printer (with error on monitor). I took off the back panel, took the paper out, and clicked to start printing again. At this point, my printer was out of ink. I put in a new cartridge, but instead of printing, it has a flashing green light.
How do I correct this?