HP LaserJet Enterprise 600 Printer M603 series - Manual (Page 199)

8. Push the fuser firmly into the product until the
blue levers on both sides click into place.
9. Reinstall the rear output bin. Insert the right
hinge-pin into the hole inside the product. Push
inward on the left hinge, and slide it into the
hole inside the product. Close the rear output
bin.
10. Plug the power cord into the product.
11. Replace the optional duplexer, if it was
removed.
ENWW Clear jams 183