HP Business Inkjet 2800

[krazeekidz3]

Hi! Just wondered if anyone has any info on the HP Business Inkjet 2800. This machine is a cutomer's machine and has a constant message that says close the cover. All the covers are closed properly! I can't even remove the covers to check the sensors. I'm sure they snap into place but I'm worried about breaking off tabs and such!!! I called Parts Now and they don't have any manuals on INKJET printers! Can anyone please help??
Thanks in advance!