1) Turn the projector completely off, unplug all cables (including all power and HDMI), wait 30 seconds, plug power back in, then see if the projector comes on with no cables plugged in (no hdmi).
2) If # 1 did not work, try reseating the lamp even though it is giving an electrical error code...
3) Also why do you not have a warranty, how would JVC know it is not the original owner, if so just tell them it was a gift or something?
I don't have any paperwork on the projector, I assume JVC needs proof of purchase for repair under warranty. The seller didn't respond to my last two emails, so I think he's out of the picture.