Issue: Our Phaser 7760 has a "Close Left Door A" that won't clear and stopped the printer.
Done: I have closed the door (duh), restarted, zapped NVRAM, cleared Tech errors, unplugged from network and wall.
Problems: Serial number doesn't show, date installed false at 1/1/00. Has been jamming various places along path using various premium color print papers in both Tray 1 & 2, no matter setting. Toner is very low, but not out.