Konica Minolta question about developer units

[Hansoon]

So that would mean that a used developer unit in good condition with a proven TCR rate of 6.5% indicating a “healthy toner concentration” would function with a new TCR-Sensor Chip. Yes?

That's what I am doing since years, and I had until now only one failure for an unknown cause. All others units were/are happy functioning for a long period until they are being rebuilt mostly because of worn seals etc. Then they are being stripped completely, equipped with new seals and of course fresh developer. Takes about an 1.5 hour in the workshop and saves a lot of money.

Hans

[copyman]

Hate to keep beating a dead horse ... I guess I'm one lucky man to have swapped at least 50 dev units in the "4" series and maybe had one or two issues. Other than that they worked great without new chip or swapping chips! Most of the dev units I've replaced have been because of depleted dev due to overlife drums, aftermarket toner, etc. Also many times I've added aftermarket developer when depleted and toned up to 6-6.5% and out the door I went. NO issues!

[femaster]

So that would mean that a used developer unit in good condition with a proven TCR rate of 6.5% indicating a “healthy toner concentration” would function with a new TCR-Sensor Chip. Yes?

That's what I am doing since years, and I had until now only one failure for an unknown cause. All others units were/are happy functioning for a long period until they are being rebuilt mostly because of worn seals etc. Then they are being stripped completely, equipped with new seals and of course fresh developer. Takes about an 1.5 hour in the workshop and saves a lot of money.

I've never actually put a NEW replacement chip on a used dev unit, where it would force the machine to reset and recalibrate, so I honestly can't say how it would react. It sounds like doing that has been working out for you, so if it has, why change? In theory, provided the dev unit was working perfectly and had a current reading right around 6.5% (+/- maybe 0.1% or 0.2%) in the machine you were pulling it from, I can't see any reason why it wouldn't work. Personally, I don't bother with new chip replacements, seems like a waste of money to me when swapping in the old chip works just fine. The only benefit I can see that bringing would be to reset the page count on the unit, but for us, page count on the dev unit is irrelevant. They get replaced only when they start to show signs of problems.

Hate to keep beating a dead horse ... I guess I'm one lucky man to have swapped at least 50 dev units in the "4" series and maybe had one or two issues. Other than that they worked great without new chip or swapping chips! Most of the dev units I've replaced have been because of depleted dev due to overlife drums, aftermarket toner, etc. Also many times I've added aftermarket developer when depleted and toned up to 6-6.5% and out the door I went. NO issues!

I have to say that you have apparently been really lucky. I've found that for the most part, the sensors are pretty close, with only minor finagling to get the levels where the copier thinks they should be. Just remember, that is what the copier THINKS the level should be based on the reading from the new sensor that the copier in not calibrated to. It will most certainly be at least slightly higher or lower of a concentration then it actually should be.

For me, I don't see any reason not to swap out the chip to guarantee a problem free replacement. In the time it takes to mess around with getting the levels to where the copier thinks they should be, I would have already swapped out the sensor and been on my way to reassembly. Technically I swap out the entire bottom plastic piece that the chip/sensor is attached to. It's a quick swap, three easily accessed screws on each unit and it's done.

[Slammers]

For me, I don't see any reason not to swap out the chip to guarantee a problem free replacement. In the time it takes to mess around with getting the levels to where the copier thinks they should be, I would have already swapped out the sensor and been on my way to reassembly. Technically I swap out the entire bottom plastic piece that the chip/sensor is attached to. It's a quick swap, three easily accessed screws on each unit and it's done.

Yeah, swapping the entire plastic assembly from the bottom is the way to go for sure, what works for me too.

The only head scratcher I have with the 4e series is the C dev being clearly empty, but the TCR still reports good i.e 6.5%. The machine never codes out for TCR depletion and the only notice you get is the customer calling in for print quality. I had one client who didn't care at all for print quality and the mag roller on the dev was actually shiny clean, unbelieveable.

[tsbservice]

Yeah, swapping the entire plastic assembly from the bottom is the way to go for sure, what works for me too.

The only head scratcher I have with the 4e series is the C dev being clearly empty, but the TCR still reports good i.e 6.5%. The machine never codes out for TCR depletion and the only notice you get is the customer calling in for print quality. I had one client who didn't care at all for print quality and the mag roller on the dev was actually shiny clean, unbelieveable.

Yep. The only one logical but still unthinkable is that TCR ratio doesn't care of exact amount of developer/toner but so as long as ratio is 6.5% it wouldn't code even there are only 50 grams of developer/toner.

[copyman]

I've never actually put a NEW replacement chip on a used dev unit, where it would force the machine to reset and recalibrate, so I honestly can't say how it would react. It sounds like doing that has been working out for you, so if it has, why change? In theory, provided the dev unit was working perfectly and had a current reading right around 6.5% (+/- maybe 0.1% or 0.2%) in the machine you were pulling it from, I can't see any reason why it wouldn't work. Personally, I don't bother with new chip replacements, seems like a waste of money to me when swapping in the old chip works just fine. The only benefit I can see that bringing would be to reset the page count on the unit, but for us, page count on the dev unit is irrelevant. They get replaced only when they start to show signs of problems.



I have to say that you have apparently been really lucky. I've found that for the most part, the sensors are pretty close, with only minor finagling to get the levels where the copier thinks they should be. Just remember, that is what the copier THINKS the level should be based on the reading from the new sensor that the copier in not calibrated to. It will most certainly be at least slightly higher or lower of a concentration then it actually should be.

For me, I don't see any reason not to swap out the chip to guarantee a problem free replacement. In the time it takes to mess around with getting the levels to where the copier thinks they should be, I would have already swapped out the sensor and been on my way to reassembly. Technically I swap out the entire bottom plastic piece that the chip/sensor is attached to. It's a quick swap, three easily accessed screws on each unit and it's done.

Once the copier is turned off and on it will go through auto calibration & stabilization and swapped unit is usually fine. If not add some developer powder or tone up manually in service mode to get "around" 6.5%. Beats spending $500 on a new dev unit! When I was servicing a lot of the 4 series I even bought a few machines just to take the dev units out. $500 for the off lease machine which is the cost of one new dev unit! I wouldn't have a problem swapping the chips but why do it when just swapping the dv units has been working for me for years!
One other thing I forgot to mention is once I have have the level to "around" 6.5%. I stabilize & do gradation ajustment.
*If you are using aftermarket toner none of this applies to you. You just can't predict what will happen with aftermarket because of the developer mixed in with Kon/Min toner.

[Dianon]

Just bringing my 25-cents forth here. With the 4e-series of machines aging out, a lot of them have been coming back in on trades for newer models, I have been salvaging the used development units from them. Any dev unit that comes in under 250K pages gets saved for future use, lower volume ones are preferable obviously. For the machines that are still out in the field that we are trying to get replaced, we don't want to invest a ton of money into them should they all of a sudden need a development unit, so we installed used units into those machines.

Straight up swapping a dev unit can be a crap shoot for sure. Every TCR sensor is different, with different tolerances in the electrical parts on that sensor board. That same sensor will have wildly different TCR readings if you were to swap it between multiple different dev units and copiers, even though those dev units would all have relatively the same toner concentration.

All new, fresh out of the box, dev units should have the exact same toner concentration, +/- a very tiny tolerance amount. The fuse contained in the TCR sensor performs 2 functions, it resets the page counts for the dev unit and forces the copier to calibrate to the new sensor. Yes, the machine calibrates to the SENSOR. The concentration is already at the ideal level in the dev unit (it's new after all), and the copier knows what that concentration is supposed to be. During calibration, the copier is monitoring the output from the sensor, and it records that reading as the baseline for the ideal TCR concentration level.

If you install a different dev unit into the copier, with a different TCR sensor that has different tolerances, the copier is going to see a value that is out of wack with what it was calibrated to. Depending on which way that TCR sensor swings, the copier might try to add more toner to that dev unit to bring the value up to it's calibrated baseline, or it could starve the dev unit of toner because the concentration now reads too high, so it will wait to add toner unit the reading has lowered to it's calibrated baseline. You may also end up with a C255X service code because the reading it is getting from the TCR sensor is so far off, that it thinks the dev unit is either severely under- or over-toned.

How do you resolve all of these problems and utilize a used dev unit? Simple. You swap the TCR chip from the ORIGINAL DEV UNIT that you are pulling out of the machine and install it onto the used dev unit you are replacing it with. Unless you are installing a new dev unit with a new chip, you do not want to use any other TCR sensor in that machine. The copier is calibrated to that sensor, and without that sensor (or a new chip to force the calibration to a new sensor), you will NEVER get accurate concentration readings. The original sensor is "married" to the machine in a sense. Yes, page counts and whatnot are going to be different, but I have never had an issue created by wildly different unit page counts. The problem has always been from using a sensor that the machine was not calibrated to.

Long story short: Take the TCR sensor off the dev unit you are removing/replacing and install it onto the used dev unit you are installing, and everything will work perfectly.

That would explain a lot.
We had the experiance, that swapping developer units between devices often fails and only works when they relativly new.
And never ever reset a used developer unit, it makes all worse.
Thougt untll now, it has something to do with wear of the unit. Never thougt on tollerances in the sensors.
Back in the old days you could swap units without problems, so i thougt the sensors would deliver always identical values with identical concentrations.

thanks, for the new insight

[occus]

I tryed to change a used DV on a bizhub c258 and a IU on a bizhub c3320i and after the TC value was 0, so it is not a good idea. After that the only solution is a new one.

A few days ago, I was forced to find a quick solution on a bizhub c250i, so I took a used DV and transferred the toner sensor from the old one to the new one. It worked perfectly.
Here's the link to my post.
https://www.copytechnet.com/forum/te...73#post1615473

Now I have a question: does anyone know if it is possible to use a black DV for a color one in the c250i series? Does it physically fit and work?

[kingarthur]

I tryed to change a used DV on a bizhub c258 and a IU on a bizhub c3320i and after the TC value was 0, so it is not a good idea. After that the only solution is a new one.

A few days ago, I was forced to find a quick solution on a bizhub c250i, so I took a used DV and transferred the toner sensor from the old one to the new one. It worked perfectly.
Here's the link to my post.
https://www.copytechnet.com/forum/te...73#post1615473

Now I have a question: does anyone know if it is possible to use a black DV for a color one in the c250i series? Does it physically fit and work?

I suspect that it does, you'll probably have to change the chip. I've noticed that when we get coloured DV units from Katun, they appear to have originally been K DV units