Dell P1500 Personal Mono Laser Printer - Manual (Page 59)

The printer is out of media, or the media did not feed properly.
What you can do:
Load media into tray 1 or the optional 250-sheet tray and press and
release Continue to resume printing.
Check that the media is loaded correctly in tray 1 or the optional 250-
sheet tray.
Press and release Cancel to cancel the print job.
What this light sequence means:
Print the other side of your duplex print job.
What you can do:
Re-insert your print job in tray 1 using the instructions in the driver pop-up
menu to orient the pages correctly.
What this light sequence means:
The printer top cover is open.