HP: Justifying Color misregistered Issues

[Orgfix]

Hello.
I want to discuss the old and dusty topic - "HP color alignment."
The purpose of the post (its further discussion) is to close this topic, at least partially.
Here goes.


1. Terminology.
The defect is googled by the words: misregistered (in SM); align, misaligned, offset, ghost (on specialized forums and "on your Internet").


2. The essence of the problem. It's here:

a2baebc5fee8.jpg


3. The general diagnosis is the discrepancy between the reference and the actual location of the image.


4. Possible causes, diagnostic methods and solutions.


Hardware reasons


Dirt on the surface of the transfer belt.
Especially true for belt without forced extraction of mining (for example, hp cp2025). Diagnosis is simple: check the surface of the belt. The solution is to clean the surface and the toner collection unit of the belt.


Dust on transfer belt calibration sensors.
Diagnostics (and solution) - sensor cleaning.


Dust or toner on the laser.
I have not seen it in my practice, but I often read on the Internet: "I cleaned the laser, everything is fine."


Program reasons


It's all more interesting. The main (perhaps the only) reason for the misaligned at the program level is the use of compatible cartridges. Or refueled.


The theory is simple: there are two types of memory in the chip of each cartridge - static (not changeable - color data, models, etc.) and dynamic. The dynamic part is for recording cartridge usage data in the printer. Such as printer data, number of copies, calibration information, etc. For this reason, it is not necessary to use a cartridge from one color printer in another printer of the same model.


There are three types of memory in the printer:
- ROM (HDD or SSD - stores firmware, utilities);
- RAM (RAM - input / output buffer)
- NVRAM (Nonvolatile Memory — stores device and user configuration settings).


We take as a basis the idea that even when using original cartridges, the color misaligned is a regular event. And when it occurs, data is exchanged between the NVRAM (which stores the data for the last calibration) and the dynamic part of the chip's memory. Data exchange occurs correctly immediately after replacing the cartridges. User does not even see that there was a misregistered picture, because the printer solved the problem without his participation. New calibration data recorded in the chip. This happened during the first calibration after the door was closed.


Another thing - refueling. We have a standard situation (it will soon have us): 4 refilled cartridges, which did not give a misregistered on the images the previous time. I refuel again (without changing the models of toner and chips). Insert in printer - misregistered. We treat hardware - no result. Let's try software treatment.


Why the calibration process did not solve the problem? There is reason to believe that the general diagnosis is always the same. It is incorrect data exchange between the chip (its dynamic part) and the part of the memory in the printer where calibration information is stored. This data is not always stored in NVRAM. Maybe in the ROM (so sometimes it helps to flashing).


We go to the practice of solving software reasons. The ideal option is to install original cartridges and reset NVRAM (or the memory area where calibration data is stored). The first calibration after such manipulations solves the problem. Also, if there is a lot of money, we change the belt, especially if service period is over.


Now there is an option in which it is impossible to replace cartridges (no money, time, out of stock, etc.).
I suggest the following sequence:
1. We erase data on the latest (incorrect) calibration. To do this, we perform two procedures (for sure): restart NVRAM and update the firmware. NVRAM is restarted with the nvram initialization, Partial Clean and similar commands. The firmware is updated in HP at a beautiful sight - just downloaded, threw via USB or network through the web admin.


2. Change the chips. Theoretically, it does not matter which ones. But if there was no problem, and then it arose, it is better to change the chip manufacturer. Often recommend Hi black or Static Control.


3. Start calibration forcibly. No stamp. One by one at least three times.


It is noticed, if you swap point 1 and point 2 - the result is zero: when you first start, incorrect calibration information is written on fresh chips.


Thank you for tolerating my bad English. I will be glad to your comments.

[tech28]

Just ran into that problem, new formatter, did the cold reset, new firmware. oem toners, IT WAS THE TRANSFER BELT! My post is in here, in the history for HP's. Good Luck.