I have an hp LaserJet 1100 which has suddenly developed a printing problem. It only prints a portion of the test print about an inch wide down the right side of the page. I have checked the half print test and the problem exists from the point of the drum and the transfer roller. Replaced toner cartridge, no change. Removed and cleaned transfer roller, no change. Feed system works perfectly. Electrical contacts on cartridge and unit appear to be in good condition. I hope that someone can help me resolve this problem. There is only a 4200 page count on this printer.