HP CLJ 2700 / 3000 / 3600 / 3800 / CP3505 Multipurpose Tray
Like most HP/Canon printers these machines have a slide in main cassette tray intended to hold up to 250 sheets of paper. The tray is plastic and can get broken. Replacements for both it and the 500 sheet tray 3 are available.
The only part of the tray to normally need replacing is the separation pad - it is visible here.
These parts are available here.