Konica Minolta Bizhub – Counter Not Resetting After Part Replacement

You have just replaced a major maintenance item on your Konica Minolta Bizhub: a drum unit, developing unit, fuser, transfer belt unit, or even a low-voltage power supply (LVPS) board. The new part is installed correctly, the machine powers on and appears ready. However, when you check the appropriate counter — whether it is a life counter, a maintenance counter, or a fault-related counter — the old value remains. Or worse, the machine still displays a “Replace Fusing Unit”, “Drum Unit End of Life” message, or an error code such as C2A12, C2412, or C-6753 persists, because the internal counter tied to that part has not been reset.

Unlike a simple “add toner” message that clears automatically, many counters inside a Bizhub machine must be manually reset after a part replacement. Failing to reset the necessary counter is one of the most common mistakes made by users — and sometimes even by less experienced technicians. In other cases, the user attempts to reset the counter, but something goes wrong: the reset does not take effect, the service mode does not allow the counter to be cleared, or the machine simply refuses to acknowledge that a new part has been installed.

In this guide, we will explain how counters work on Konica Minolta Bizhub machines, differentiate between parts that require a manual reset and those that have automatic “new release” detection, and provide a systematic approach to diagnosing and fixing counter reset failures.

Understanding Counters on Konica Minolta Bizhub Machines

Before diving into troubleshooting, it is essential to understand the different types of counters and how they behave.

User / Meter Counters — Track total prints, copies, and scans. These are rarely involved in “part replacement” issues, but they can be reset erroneously and cause confusion.
Life Counters (Maintenance Counters) — Track how many pages or hours each maintenance part has been used (e.g., drum rotation time, fuser usage, developer print count). These counters typically require manual reset after replacement.
Toner / Supply Counters — Directly tied to the smart chip on toner cartridges. These usually clear automatically when a new genuine cartridge is installed because the new chip contains a “new” flag that the machine reads.
New Release Counters (Automatic Detection Parts) — Certain parts such as drum units, developing units, fusing units, and transfer belt units on Bizhub models have an electronic detection function. When a brand new genuine unit is installed, the machine detects that it is new and may automatically clear the life counter. However, this automatic “new release” is not foolproof, and many models still require a manual reset procedure.
Special / Soft Switch Counters — Some counters can be disabled or configured via soft switches in service mode. For example, a “drum end of life” message can be turned off without resetting the counter. These function differently from true counter resets.
Fault / Service Call Counters — Count how many times specific error codes (C-XXXX) have occurred. These can be cleared via Service Mode -> Counter -> Service Call.

The key distinction: some counters can be cleared manually by selecting the part and pressing “Clear” or “Counter Reset”. Other counters — specifically those for parts with a “new unit detection function” such as the fusing unit, transfer belt unit, drum unit, developing unit, and TCR new article detection — may not allow manual clearing. For those, you must use the proper “New Release” procedure for the machine to acknowledge that a new unit has been installed.

Possible Causes

Operator error — the technician did not perform the required counter reset or new release procedure after part replacement.
Failure to enter the correct Service Mode or to follow the correct menu path for the specific model and part.
Using a second-hand or non-genuine part that has already had its “new unit” flag consumed, or that does not contain a functional smart chip.
Using a brand new genuine part, but the machine’s new unit detection mechanism fails due to dirty contacts, a stuck sensor flag, or a damaged actuator.
A defective control board (MFPB, PRCB, or CPUB) that does not properly store the cleared counter value or does not communicate correctly with the part’s chip.
Corrupted NVRAM (Non-Volatile Random Access Memory) where counter data is stored.
Firmware bugs — older or corrupted firmware may prevent counter resets from completing successfully.
Counter locked because of an ongoing C-XXXX error code that must be cleared first. Some service modes are disabled when a critical error is active.
The counter reset was undone inadvertently because the technician pressed “Interrupt” or exited service mode incorrectly.

Step-by-Step Troubleshooting

Start with the most basic checks and progressively move to more advanced diagnostics. The most common cause of a counter not resetting is simply that the technician did not know which procedure to follow.

Step 1 – Determine the Correct Reset Method for Your Part and Model

First, understand that not all parts require the same reset method. On Bizhub machines, there are three primary reset approaches:

Manual Clearing via Life Counters — Some parts (including older drum units without smart chips, paper feed kits, some maintenance counters) can be cleared manually.
- Enter Service Mode.
- Navigate to [Counter] → [Life].
- Select the specific part (e.g., “Drum Unit (K)” or “Fusing Unit”) and press [Clear].
- Confirm when prompted.
- Power cycle the machine.
Counter Reset menu — On many models, there is a dedicated [Counter Reset] function.
- Service Mode → [Counter] → [Counter Reset].
- Select the specific counters to be cleared and touch [END].
- Touch [Execute] to clear the selected counter values. (Refer to the Service Manual for your specific model.)
New Release Procedure — For parts that have a new unit detection function (fusing unit, transfer belt unit, drum unit, developing unit), a manual clear is typically not sufficient. The machine requires a specific “New Release” process.
- Service Mode → [Counter] → [Life] → [New Release].
- Open the front door or lower front door as instructed on screen.
- Select the unit where New Release is made.
- Press the Start key to perform the New Release.

1.1 Special Cases: Function Code 88 (Maintenance Mode Counter Reset)

On some Bizhub models (e.g., 4000i, 5000i, 4020i, 5020i), the LVPS (Low-Voltage Power Supply) and certain other parts require a “MAINTENANCE 88” procedure. This reset is not performed in standard Service Mode but in a separate Maintenance Mode. The Function Code 88 resets the “Irregular Power Supply Counter” or other specialized counters. Consult the Service Manual for your model to see if Function Code 88 applies for the specific part you have replaced.

Step 2 – Verify the Part is Genuine and Compatible

If you have performed the correct reset or New Release procedure and the counter remains unchanged, the next suspect is the part itself.

Check that the part you installed is a genuine Konica Minolta part. Many compatible parts either lack a smart chip entirely or use a chip that does not fully emulate the original new unit detection behavior.
If you are using a compatible part, confirm with your supplier that it supports the “new release” function. Some compatible parts require a manual counter clear via Life Counters but will not work with the automatic New Release procedure.
If the part is a genuine Konica Minolta unit but was previously used in another machine, its “new unit” flag may have already been consumed. The machine will not recognize it as new. Always use brand new sealed genuine parts when performing a New Release.
Visually inspect the chip on the part. Are the gold contact pads scratched, dirty, or missing? A missing or damaged chip will prevent new detection.

Step 3 – Clean the Chip Contacts and Check the Sensor Mechanisms

Even if the part is brand new and genuine, the electrical communication between the chip and the machine can fail due to contamination.

Power off the machine, unplug it, and wait for it to completely discharge.
Remove the part (drum unit, developing unit, fuser, etc.).
Locate the smart chip on the part. Using a soft, lint-free cloth, gently wipe the gold contact pads. If stubborn residue is present, you may use isopropyl alcohol (90% or higher). Allow the chip to dry completely.
Inside the machine, locate the spring-loaded pins or metal fingers that make contact with the part’s chip. Gently blow compressed air into that area to remove dust. If necessary, use a dry cotton swab very gently. Do not bend the pins.
For drum units and developing units, check the small mechanical actuator or flag inside the machine cavity that signals that the unit is fully seated. If this flag is stuck due to toner dust, the machine may never register that a new unit has been installed.

Step 4 – Perform a “Trouble Reset” First (If an Error Code is Active)

In some situations, an active error code such as C-6753 (non-genuine toner detected) or a C-xxxx service call can block the counter reset procedure. The service mode may be partially disabled until the error is cleared.

While holding down the Utility/Counter key, turn the main power switch ON. Continue holding the key until the service mode appears.
Alternatively, for some models, enter Service Mode via the standard key sequence (e.g., Stop → 0 → 0 → Stop → 0 → 1).
Navigate to [Trouble Reset].
Touch [OK] or press the Start key to perform the trouble reset.
The machine will cycle power. After the reboot, attempt the counter reset or New Release procedure again.

Step 5 – Try Resetting the Counter via the “Initialization” Menu

Some Bizhub models have a “Counter Data” reset located under [System 1] → [Initialization] → [Counter Data]. This approach may work when standard Life or Counter Reset methods do not. However, exercise extreme caution. Initializing Counter Data can affect multiple counters, including meter counts. (Refer to the Service Manual for your specific model to determine whether Counter Data initialization is appropriate.)

Step 6 – Check for Soft Switch Interference (User / Admin Settings)

On certain Bizhub models, the “replace drum/fuser” message can be suppressed via soft switches without resetting the underlying counter. Soft switches may also prevent certain messages from appearing even after a counter reset.

Enter Service Mode and navigate to [System 2] or [Engine FW DipSW] (the exact location varies by model; refer to the Service Manual).
Look for soft switches related to drum or fuser life end message suppression.
If these soft switches have been changed from their default settings, they may interfere with the normal counter reset behavior or cause false messages to persist.

Step 7 – Update Firmware

Firmware bugs can cause counter reset procedures to fail. Check the Konica Minolta service portal for firmware updates for your specific model. Release notes often mention fixes related to life counters, new release detection, and counter reset stability. This procedure requires access to official Konica Minolta firmware and service tools. If you are not a certified technician, contact your service provider for assistance.

Step 8 – Advanced Diagnostics: Counter Data Storage (NVRAM & Control Board)

If everything else has failed, the problem likely lies in the machine’s hardware that stores and processes counter data.

8.1 Inspect Connectors and Wiring

Access the control boards (MFPB, PRCB, CPUB, FRB, etc.) inside the machine. The exact connector names and board locations vary by model. Consult the Service Manual for your specific model to identify:

Connectors that carry signal data from the part’s chip to the main board.
Connectors that supply power to the NVRAM or backup battery circuit.

Visually inspect connectors for bent pins, corrosion, or loose seating. Reseat all relevant connectors firmly.

8.2 NVRAM (Non-Volatile Random Access Memory) Corruption

Counter data is stored in NVRAM on one of the control boards. If NVRAM becomes corrupted, counter values may not update or clear correctly. NVRAM initialization is possible, but this is a last-resort procedure that clears many settings, including calibration data and user settings. Never perform NVRAM initialization without first backing up the machine settings. (Refer to the Service Manual for the NVRAM initialization procedure.)

8.3 Failed Control Board

In rare cases, a defective control board may prevent counter values from being stored or retrieved correctly. If you have exhausted all other possibilities, replacing the board responsible for the relevant counter may be necessary. The service manual for your model will indicate which control board is associated with each counter.

Step 9 – Check for Inadvertent Undo (Interrupt Key)

After a technical counter clear is performed, the machine may undo it if the Interrupt key is pressed or if the service mode is exited incorrectly. This is more common on older Bizhub models. When clearing a counter, ensure:

You confirm the clear action when prompted.
You do not press the Interrupt key afterward unless you intentionally want to undo the action.
You exit Service Mode properly (usually by pressing the Reset key multiple times or power-cycling the machine).

Summary Diagnostic Table

Symptom	Most Likely Cause	Action
Drum / IU life counter not resetting after drum replacement	Operator did not perform required New Release procedure	Service Mode → [Counter] → [Life] → [New Release] → select drum unit
Fuser / Transfer Belt counter not resetting	New Release procedure required instead of manual clear	Service Mode → [Counter] → [Life] → [New Release] → select unit
C-6753 / Non-genuine toner error persists after genuine toner installed and counter reset attempted	Toner chip contacts dirty or defective MFP chip communication	Clean chip contacts; perform Trouble Reset; if persists, replace MFP board (refer to service manual)
Partial reset: counter value goes down but not to zero	Second-hand part or chip that has already been used	Replace with brand new sealed genuine part
Counter reset completes but same warning message returns immediately	Dirty or stuck drum / fuser detection actuator	Clean actuator mechanism inside the machine; ensure part is fully seated
Unable to enter Counter menu in Service Mode	Active C-xxxx error code blocking service access	Perform Trouble Reset first, then attempt counter reset
Counter reset works for some parts but not for others	Faulty control board or NVRAM corruption affecting specific address ranges	Backup data, initialize NVRAM, or replace the relevant board (consult service manual)

Model-Specific Notes

Bizhub 423, 363, 283

On these models, the drum unit does not have a new article detection function. Therefore, after replacing the drum unit, you must manually reset the “Drum Unit Rotation Time counter” using Service Mode → Counter → Life. Failing to do so may result in image fogging and toner splashing.

Bizhub C658 / C558 / C458 / C368 / C308 / C258

These models allow a “New Release Disable mode” for troubleshooting. If you have used this mode, you must turn it off and then perform New Release normally. Also, before reinstalling a previously used drum unit, check the life counter reading to confirm that New Release was not accidentally performed on it.

Bizhub C360i, C300i, C250i

For the fusing unit and transfer belt unit, perform New Release. It is not possible to manually clear the counters for the fusing unit, transfer belt unit, drum unit, developing unit, and TCR new article detection.

Bizhub 500

Some technicians report being unable to reset the fuser counter after rebuilding the fuser. In such cases, try powering off the machine and rebooting while holding down the Utility/Counter key, then enter Service Mode directly rather than through Trouble Reset.

Bizhub 250 / 350 (Black & White)

For the fuser unit, manual reset is not required. For the drum unit, access Tech. Rep. Mode → Counters → Special Parts Counter → PC Life and press the Clear key.

Preventive Measures and Best Practices

Always consult the Service Manual before performing any reset. The exact menu paths, key sequences, and available options vary significantly between models and firmware versions.
Write down current counter values before resetting. If you clear the wrong counter by mistake, some models allow an immediate undo by pressing the Interrupt key. Once you exit the menu, the undo option is lost.
Use only brand new, sealed genuine Konica Minolta parts when you expect the New Release function to work automatically.
Keep a log of when maintenance parts were replaced and which counters were reset. This discipline helps track machine health and avoids confusion.
Check firmware version before troubleshooting. Some counter reset problems are simply known bugs that have been fixed in a later firmware release.

When to Call a Certified Technician

The following situations require the intervention of a certified Konica Minolta technician:

You have followed all of the steps in this guide and the counter still does not reset.
You need to perform a New Release procedure but are unsure of the exact menu path for your specific model and firmware version.
The machine is showing an error code (C-xxxx) and a simple Trouble Reset does not clear it.
You need to perform NVRAM initialization or replace a control board.
You need to update the firmware.

Conclusion

A counter that does not reset after replacing a maintenance part is a frustrating problem, but in most cases it is not a hardware failure. The most common cause is simply using the wrong reset procedure for the specific part and model. Always remember: for parts with a “new unit detection function” (fusing unit, transfer belt unit, drum unit, developing unit, TCR unit), use the New Release procedure, not the manual clear. For parts without new detection, locate the correct life counter and clear it manually.

By following the structured approach in this guide — from verifying the correct procedure, to checking the part compatibility, to cleaning contacts, to advanced board-level diagnostics — you can successfully resolve virtually any counter reset issue on a Konica Minolta Bizhub machine.

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