Take out the cartridge and clean it with vacuum cleaner, as well as the printer. Then shake the cartridge above clean paper, check if there are some toners coming out. After that, try to print again for at least 80 pages of text print sample. Open the printer and check the cartridge if still leaking. Inspect the OPC, and if there is any scrap,clean it. Fiber of paper will be accumulated inside printer. Printer needs to be maintained regularly. If leaking appears repeatedly, replace the cartridge.