BH-C-280, C2557

[Hansoon]

BH-C-280, C2557

Machine has 55.997 mono/55.331 color pages on the clock. Suddenly tiny black spots and a spotty slightly black "overtonered" looking background came up. All TCR readings are around 6.xx% and TCR-K had 6.22%. Since I have no new K-developing units at hand, I took from one of my stock machines a very good working K-developing unit with around 80K on it and tested it, to be sure, in my office machine which also had originally a K-unit around 70K or so.

I was able to switch those K-units without problems backwards and forwards between the machines so I was confident that swapping of units, though undesired, would be possible. However, later at the customers machine I got, with the previously tested and good working K-unit, after around 10 prints a C2557. The TCR-K was showing 2.41%. After putting back the original unit everything was OK except the before mentioned print quality ofcourse. Putting the replacement K-unit back and executing manual TCR-K toner supply, machine appeared to be extremely overtonered with black toner.

A 3rd K-unit from my stock machines showed exactly the same behavior, this time starting with a TCR-K of 1,98. For the moment the machine is running with the original developing unit but the customer wants the issue to be solved.

Question: Can this swapping of units really be that critical? Would the only solution be a new unit and is setting it up with the TCR set up procedure inevitable?

Thanks

Hans

[Max]

Re: BH-C-280, C2557

Yep its critical. The dev unit has to be initialized otherwise you get error codes. Or you can get new dev reset chip so it will initialize used dev and treat it as new. (works most of the times)

[allan]

Re: BH-C-280, C2557

Jip the characteristics of the chips vary a lot. Next time you face an issue like this swap the TCR chips to entertain yourself. The readings from the same tank can change as mutch as 5% with the same ratio toner in the dev.
The 6.5 percent is mixed at the factory. If the ICP on the chip pops the machine assumes the mix is 6.5% and maps the voltage from the sensor to match. It does not calibrate the dev mix instead it reads the sensor.
So yes you have to reset it to make sure you don't get the pest of a code.

...Short out pin 1 and 5 on the dev connector and make the door switch for about a second. Hate going back for stuff.#


And then there is the possible dev buildup on the magnet inside the hopper.

[Ali Hamed]

Re: BH-C-280, C2557