Dell 3333/3335dn Mono Laser Printer - Manual (Page 292)

You need to know your printer model type and the Service Tag number or Express Service Code. For more information,
see the label on the inside top front cover of the printer. The Service Tag number is also listed on the menu settings
page.
For additional technical support, check the Dell Support Web site at support.dell.com.
Troubleshooting 292