I am getting a 39,012.41 error message on a C2424 which refers to (doc feeder optical test failure) The suggstions in the service manual say to cycle power or replace doc feeder. When you shut the copier off and on it will work until it goes into sleep mode for a long period of time then it will error out when you try to use it. I have already replace the whole doc feeder with the scaner unit. I checked customers power and have it pluged into a surge protector with a 4.6% drop Have tried two different plugs and two different surge protectors. If anyone has seen this or has any sugestion please notify me as soon as you can customer is starting to get irritated.