Hey guys, I have an E-Studio 720 with a CF70 and I am unable to make a change in the machine. Customer's initial complaint was that the copies were washed out, but before I could arrive the machine threw a CF70 error code. After spending an hour vacuuming up what seemed like the entire toner bottle inside the machine, i started by doing a pm. I replaced the main corona wire, swapped to a known good developing unit with fresh DV, replaced the drum cleaning blade and made sure the recycling auger and toner hopper turned freely. After stirring the developer and bringing the machine to READY. I was able to get the machine pass 1 sheet of blank paper. After that the machine immediately goes into CF70 error. After rebooting, the machine always come to a ready state, but once copying starts the paper stops at the drum and immediately errors out. I thought maybe it was related to the main corona coming on, but it appears I am unable to make a change. After checking the other CF70 error posts, I am unable to find a direction. It seems that solutions don't generally get posted. Any ideas what a real world solution is? I know the service manual suggests a logic pwb issue, but I am not convinced that is a REAL world solution. Do I need to go back and check the mechanical operation or is this a problem being masked somewhere else ?
Maybe I should start another thread about how solutions don't get posted???
I've seen this a few times in the field. How many copies does this machine have? This model is known to have the harness to the little bitty toner motors bind up because the wire gets a nick inside the insulation. Usually the solution is to change the harness with the motors to the toner hopper. There are two on top and theres one right underneath the actual toner. Hope this helps.
[CF70] New toner transport motor abnormality (1) Check if the transport auger and paddle are not locked (no extraneous material or toner clod in
both the toner transport sections at the cleaner unit).
(2) Is the new toner transport motor disconnected?
(3) Check if the connector of the LGC board and connector Pins are not disconnected.
(4) Replace the new toner transport motor.
(5) Replace the LGC board
Success! I was able to repair my machine. It was NOT a pinched wire harness. The actual solution to my problem was fresh developer and a THOROUGH cleaning of the NEW toner hopper (not the recycling auger). The lower augers were jammed with toner. There was no way the augers were going to turn. The machine just wanted to keep adding and adding toner to the DV unit until it wouldn't hold any more causing the backup in the toner hopper. No parts were needed. Thank you everyone for your support.