Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
Run a few pages off. Perhaps it will simply clear out the (probably) leaked-toner-caused stripes.
Was the printer left open at any time, from just before it was disused, through its period of disuse, or just recently?
If the above treatment doesn't work, a cleaning procedure I will give you would be appropriate. Let me know how it goes, and how far apart the stripes are, along the page, and I will advise you further as appropriate. (A scanned-in picture of the print defect, attached with your reply, would help with the process.)