HP LaserJet P4015 Printer series - Manual (Page 179)

3. Make sure that the paper is flat in the tray at all four corners and below the maximum-height
indicators.
4. Slide the tray into the product.
5. Press OK to clear the jam message.
6. If a jam message persists, a sheet is still jammed in the product. Look for the jam in another location.
See
Jam locations on page 161 .
Clear jams from the optional 1,500-sheet tray
1. Open the front door of the tray.
ENWW Jams 167