HP OfficeJet Pro 7740 - Manual (Page 32)

8. Reinsert the input tray into the printer.
NOTE: When you insert the input tray, the input tray extension remains outside of the printer.This is
the expected result.
9. Pull out the output tray extension to the A size marking.
Pull out the output tray extension to the B size marking.
To load an envelope
1. Pull out the input tray completely.
ENWW Load paper 19