C-7 980 error code

That code indicates that there is a problem with the waste toner bottle either being too full, which means that it must be either emptied or replaced, or that the sensor that senses the amount of toner is defective. You should have got an E-31 code in conjunction the C-7 980. the only thing that you can do is change the waste toner bottle, after that you're going to have to get technical help in person. Sorry. Let me know if this helps.