Black pages when making a copy or printing something

Have you tried both drum and toner supplies? cause it sounds like a drum fault, if you have tried a new drum and toner, and it is doing it when printing internal reports, receiving fax's and copying then you have a tecnical issue to do with charge and this would likely render machine unecomical to repair (unless you can find a bad contact with drum on machine). If it receives faxs clearly but copys black then it is different issue (ie optics).