I have a KM 5050 with 500K on has worked fine till now. When it goes from sleep mode to ready state C6020 comes up. When sleep mode is set to 4 hours problem does not occur. Customer wants to use short sleep mode. The machine has the latest firmware,and the modifications to the fuser connector have also been done, and the fuser has been replaced, and I have done a complete factory reset. Any ideas ?????

Have you tried downgrading the firmware a couple levels?

Yeah, tried that, still throwing up fuser error code, saw a post by Mark fron UK team re seperating the cables from the fuser connector on the machine side , did that, and the problem has gone away. Thanks Blackcat 4866 for your suggestion, and thanks Mark for your wonderful post. Just checked the new Taskalfa 400 and the fuser wires are seperated in the same way as Mark has suggested !!! Amazing that Kyocera did'nt post that as a service buletin.!!!!!!

typerated, re seperating the cables? thanks. ML.