That code is toner supply abnormality. As already mentioned above, its usually a blocked toner pipe, sealing tape still on the cartridge or toner has become hard in the cartridge due to incorrect storage. The WTB has nothing to do with this.
How could you tell if the WTB was overflowing with cyan only? If the WTB was full, it would trip the waste toner motor clutch.
There was cyan toner that was all over the outside of the WTB. Could it be that the waste cyan was clogged leading to that code? I don't know much about the Sharp machines to be able to say that it was 100% the WTB. All I know is the last thing I tried was changing the WTB so I assumed that did it :P
If you have any toner covering the outside of the WTB, it is almost for certain, that there has been toner spilt from a new cartridge when installing it. It always tends to fall down over the area below the toner cartridges..... right over the outside of the WTB. I'd say that it was a very poor attempt at installing a new cartridge, rather than a WTB fault.
If you didnt check the toner pipe, shake the crap out of the toner cartridge, confirm the dev unit drive belt is OK and not seized up and the tape is fully removed from the cartridge, then it just might come back.
However, something to keep in mind..... If the client has been removing & inserting that toner cartridge (and toner dropping out of it in the process), there is a chance the CRUM chip has blown or the cartridge was not 100% installed fully, eventually leading to the toner supply trouble code.
If everything is seated OK, then it should be OK. One way to confirm toner is flowing correctly again, is run solid cyan pages through it in sim 64-01. Change A to 1, select C for cyan, select multicopy and run it continuously. The machine will pause for a few seconds when it is replenishing toner. If it continues OK after this small pause, then you know toner is flowing OK between the cartridge & dev unit.
Thanks for the tips. I'm the IT Manager for the office so I have general knowledge of everything but not specific enough to do all of the troubleshooting advice you gave. There's some cyan lines at the top of some pages but I think that's because the drum+dev are over 100k now. I have a tech coming in to change those so I'll get him to check out the things you mentioned while he's here on the clock.
Just an update on this code (and associated F2-64, 66 & 67).
Had 2 calls yesterday with this trouble code, with the exact same cause, not mentioned here on this post as yet. I know this post is already closed, but maybe this extra info might help someone in the future.
Both machines were low page count, high drum rotation machines in a hot room. F2-65 error constantly appearing each startup. Found the CMY drums so badly worn on the rear frame that bare metal of the drum surface was so exposed that it had actually cut a deep ridge into the aluminium. The deep ridge was full of developer and was causing a massive drum surface potential increase & constant charging of the drum. This was constantly pulling toner as the machine was feeding toner in.
As usual, after the process control timeout, the error appeared, showing that there was a 'toner supply abnormality', whereas infact, the toner was supplying perfectly fine but the developer was unable to come to ready due to toner constantly passing through to the badly worn/damaged drum.
Funny part was, the developers were OK. Usually when there is excessive toner pull from the developers, the dev usually goes with it, eventually emptying the dev unit and straight into the waste toner box.
3 new color drum units as required, color calibrated and all back to normal. Confirmed all other causes of this problem were OK. Confirmed toner replenishment sequences OK during long high coverage print runs.
Moral of the story........... Check the drums (even if clean & low page count) as well as the usual toner pipe, toner cartridge, developer drive belt and toner coupling which primarily cause this code.