In my office we have one HP 4050N printer. I have inserted a new printer toner cartridge after removing polytheen lable inside the Toner cartridge. In printer control panen display , NEW TONER CARTRIDGE=NO * is displayed. I have changed this to NEW TONER CARTRIDGE=YES* but the change didn't take effect. It is printing only blank pages. I have tried from different machines and different applications. Still the same problem persists. Please help me to resolve this issue.