BH 754 does not want to reset Developer Unit counter

[aazim]

Bizhub 754. Total counter - 1 231 000. Replaced Developer and drum units simultaneously. Both new, OEM, in boxes. After switch ON - Drum unit counter was reset 0M/100% , Developer unit counter- not. I reset maintenance, toner and ozone filters counters - both was replaced too. Check the manual -lead me to Gradation Adjust after replacing Drum Unit. The working day is going to end and I leave. The next morning a print job was sent to machine-about 40 A4 and when I came C-2558 waiting me. C-2558 - Abnormally high toner density detected black TCR sensor. Run 5 A3 Gray - Halftone-70, [Imaging Process Adjustment] -> [Stabilization Only], [Image Process Adjustment] -> [Gradation Adjust]-several times and in the end the Conv. Value was in the specific range.
The machine now work, quality is great but DevUnit count is still 1 231k/0%. Check and recheck coupling between DevUnit and machine. Observe the old unit - there is 1 chip/board-5pins who seems to toner concentration sensor-suppose reset counter chip is also there. The other 3 pins are for reading the drum unit chip.
Did I miss some in the procedure? Or have bad(or partly) Dev Unit chip?

[EarthKmTech]

Bizhub 754. Total counter - 1 231 000. Replaced Developer and drum units simultaneously. Both new, OEM, in boxes. After switch ON - Drum unit counter was reset 0M/100% , Developer unit counter- not. I reset maintenance, toner and ozone filters counters - both was replaced too. Check the manual -lead me to Gradation Adjust after replacing Drum Unit. The working day is going to end and I leave. The next morning a print job was sent to machine-about 40 A4 and when I came C-2558 waiting me. C-2558 - Abnormally high toner density detected black TCR sensor. Run 5 A3 Gray - Halftone-70, [Imaging Process Adjustment] -> [Stabilization Only], [Image Process Adjustment] -> [Gradation Adjust]-several times and in the end the Conv. Value was in the specific range.
The machine now work, quality is great but DevUnit count is still 1 231k/0%. Check and recheck coupling between DevUnit and machine. Observe the old unit - there is 1 chip/board-5pins who seems to toner concentration sensor-suppose reset counter chip is also there. The other 3 pins are for reading the drum unit chip.
Did I miss some in the procedure? Or have bad(or partly) Dev Unit chip?

I've had this before, the dev unit is a dud, just replace it.

The error code is because the machine was unaware a new dev unit was installed and did not perform tcr sensor calibration.

replace it, claim under warranty if required.