HP OfficeJet Pro 7740 - Manual (Page 122)

To clear a paper jam from Tray 1
1. Pull Tray 1 out of the printer completely.
2. Check the gap in the printer where the input tray was. Reach into the gap and remove the jammed paper.
3. Insert Tray 1 back into the printer.
To clear a paper jam from Tray 2
1. Pull Tray 2 out of the printer completely.
ENWW Jams and paper-feed issues 109