When do you use U140 (Developer Bias Adjustment)?

[PrintWhisperer]

Re: When do you use U140 (Developer Bias Adjustment)?

If you are an authorized dealer, just have your SSE out for a problem call, and happen to walk him past the toner cage holding that aftermarket crap. Maybe have him take a couple pics.

The problem will be taken care of.

[KYO_OEM]

Re: When do you use U140 (Developer Bias Adjustment)?

Up to now i read a lot of posts but no real answer.
What`s behind U140 without crystal ball?

I will share my small knowledge with you:
It`s needed for dual component development systems with a-Si drums only

If the AC bias is low, the density uniformity (solid pitch unevenness) deteriorates, and if it is high, development leakage occurs.
Since the AC bias is used at an appropriate value (depending on the gap between the drum and the developing roller and the carrier resistance), set the optimum AC bias by combining the developing roller and the drum.　
*The developing current detection circuit in the high voltage PWB measures the amount of developing current to detect saturated AC bias.

After exchange from DK and/ or DV units, you has to run U140 to get correct AC Bias values.
For the new generation of Iris high series (xx54ci >35ppm) KDC implemented new funtionallity:
AC calibration automatic execution timing!!　
- When the developing unit or drum unit is replaced and the S/N changed.
- Every 500k by color dot counts in engine. >> Execute by YCM, K.

For all "older" systems with inbuilt a-Si drum you has to perform it manually.
e.g. after new drum
119, drum setup, to read and store important surface data
930, to compare/ set MC voltages by correct counter data
140, see explanation above
464, to get correct 3 and 8 step density data + pre registration
469, for correct full color registration
412, for even density (only needed for older systems, on xx54ci only just in case)
464, to get new real density data after maybe uneven density (older systems only, not needed again for xx54ci)
410, important point for 256step halftone density data

I prefer to use U952 MK-B in case of DV and/ or DK exchange on Iris series.
By using this workflow you can`t forget any needed adjustments.

Finally to prevent requests regarding U464 data, i attach short explanation about it.

[Copier Mechanic]

Re: When do you use U140 (Developer Bias Adjustment)?

Up to now i read a lot of posts but no real answer.
What`s behind U140 without crystal ball?

I will share my small knowledge with you:
It`s needed for dual component development systems with a-Si drums only

If the AC bias is low, the density uniformity (solid pitch unevenness) deteriorates, and if it is high, development leakage occurs.
Since the AC bias is used at an appropriate value (depending on the gap between the drum and the developing roller and the carrier resistance), set the optimum AC bias by combining the developing roller and the drum.　
*The developing current detection circuit in the high voltage PWB measures the amount of developing current to detect saturated AC bias.

After exchange from DK and/ or DV units, you has to run U140 to get correct AC Bias values.
For the new generation of Iris high series (xx54ci >35ppm) KDC implemented new funtionallity:
AC calibration automatic execution timing!!　
- When the developing unit or drum unit is replaced and the S/N changed.
- Every 500k by color dot counts in engine. >> Execute by YCM, K.

For all "older" systems with inbuilt a-Si drum you has to perform it manually.
e.g. after new drum
119, drum setup, to read and store important surface data
930, to compare/ set MC voltages by correct counter data
140, see explanation above
464, to get correct 3 and 8 step density data + pre registration
469, for correct full color registration
412, for even density (only needed for older systems, on xx54ci only just in case)
464, to get new real density data after maybe uneven density (older systems only, not needed again for xx54ci)
410, important point for 256step halftone density data

I prefer to use U952 MK-B in case of DV and/ or DK exchange on Iris series.
By using this workflow you can`t forget any needed adjustments.

Finally to prevent requests regarding U464 data, i attach short explanation about it.

Than you for the information. You are very generous, appreciated it!!

[koopman]

hello

the developer bias adjustement U140 is the best because is the only way i know to make the copy darker. The problem is that after a few minutes or so its values changes by itself . For example i introduce 285 value for color developers and later goes again to 250 wich is too light. Its a Kyocera 3252 ci. Any help ? thank you all

[koopman]

even more. There are two machines 3252ci . One of them im always increasing the bias values. In the other im always lowering them. How could i keep them steady? Or how can i make the printing from computer lighter or darker ? thank you

[Lunatech]

even more. There are two machines 3252ci . One of them im always increasing the bias values. In the other im always lowering them. How could i keep them steady? Or how can i make the printing from computer lighter or darker ? thank you

System menu/printer/toner saver level (ecoprint) I have had to use this on occasion with mixed results.

FWIW I hope this helps.