HP 3840 - Manual (Page 12)

5. Raise the In tray.
6. Reach underneath the In tray, and then lift the tray until it locks into place.
7. Lower the printer cover.
4.4 Print cartridges
Three print cartridges are available for use with the printer.
1. Tri-color print cartridge
2. Black print cartridge
3. Photo print cartridge
HP Deskjet 3840 series printer User's Guide
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