bad color registration and magenta banding mx-5000

[Froota]

Hi,

I lost a lot of time today after searching for a solution on a mx-5000.
As we went to the customer to fix a problem with banding on color prints, they showed another color print with bad color registration.

So I checked the colors by making a registration adjustment. (50-22) and I saw that yellow was far beyond its value.
Because of that I checked the position of the Lsu and had to adjust it's position to the middle, and I made a 61-04. (image writing adjustment)
After I did this, I repeated from the start by making a 50-22 and now I got an error on Magenta. (main magenta front 72)
Even with the 50-20/50-21 we could not turn back the level to normal. Even Yellow was far away from his position.

I took a step back and returned the lsu one position back between middle and right, and then we could make a 50-22 with a good result. But in the 50-20 magenta made some very strange things. (see attachments)
We checked the position again of the Lsu, cleaned ID sensors, made a process control......without results.
So know we can make a 50-22, but the color registration is far from good! very strange.

In the attachement I also sended an example of the banding we had, because it's also in magenta. (full color, 64-01/1)
I don't know if this problem has something to do with the other.

At the end I founded the code F2-39 (Process thermistor breakdown). Maybe this could help...


Any ideas?

regards,

Froota1.jpg2.jpg3.jpg

[btbear]

Check and make sure the gear on the primary transfer belt has not broken. I have had these break where they hold the pin on the shaft and cause all kinds of registration and banding problems. Have also gotten DV unit errors because the timing for the test patch is off. Good luck.

[Froota]

Check and make sure the gear on the primary transfer belt has not broken.

thx for the fast respons.

Do you mean the big white gear on the back right, that drives the belt around?
We checked transfer load and it changed in all 3 positions (color, black and free).
Also we are able to make prints like those above, so i suppose that the belt is turning.

[bonnie750]

Yes that's the gear,part of the x1 kit. the gear may appear ok until you take it off and the broken part which is held by the pin falls away.This uaually
shows as bad registration on copies though I suppose it can manifest itself in many ways depending on how loose the gear is....Worth a try.

Bill

[igi]

hi
have you tried another magenta dv-box
good luck

[Lawrence]

How many copies on the machine?

I would agree with BT and Bonnie, pull that gear off and look at it from the back side to see if it's cracked or worn where the pin sits. If your belt does not turn at a constant rate every thing goes all to hell when it comes to registration. I would expect to see problems in cyan and yellow as well but from the test print that you can see they look even but this is a good place to start.

Have you tried swapping the magenta drum with cyan to see if the misregistration follows? Make sure your DV unit turns smoothly as well.

Also make sure your procon sensors are clean. There are the 3 little doors to the right of the black drum that cover the sensors.

You can also try changing Sim 50-10 BK-Mag=100
Ive had that help with Yellow or Magenta or Cyan errors (new machines) before but it does sound like you have something mechanically wrong.

If your transfer belt is getting near the PM mark you can replace the entire belt cheaper vs rebuilding it. The downside is you don't get a PTC with the new belt.

[mojorolla]

Pull the toners and run SIM 25-1. I have seen a few mag rolls in these go bad. If the magenta is real low (60) or maxed (255), you have a bad DV unit.

[Froota]

Hi,

I went back to the customer to try some things out.
I had some doubts about the transfer driving gear, because other colors were good, and we had no errors on the belt.
But I checked it to be sure and the transfer belt also turned fine. Also the ID sensors are fine.

I emptied the magenta dev. box to see the movement of the dev. roller, but it looked fine.

Most of the time I get the magenta front 72 error after the 50-22, except if I change the position of the laser to the right.
Then the result of the 50-22 is ok, but the registration is so bad. Even yellow is far beyond his value.
I removed the laser once to see if there was nothing vissible, but it all looked fine.

After my last visit the customer could make good prints for the whole day, and the day after the registration went wrong again.
Also look at the (bad) picture in attachment, with the results after the 50-22.
You can see that there's nothing modifiable on magenta front. It's value is too low.

I will try with a new magenta dev. unit, but i have my doubts because the yellow.

There is about 100K on the main counter of the machine, so nearly new for this kind of machine.

if there are other proposals let me know...

thx in advance!

[benn84]

Hi
I'm having a similar problem to what your getting - colour reg off and the error ' main magenta front 72' and ' main yellow front 82' I have checked transfer drive gear - OK. Colour reg is very bad - advice please
Regards
Ben

[igi]

hi all
please try this

Symptom:	Main Magenta Front or Main Cyan Front Error after executing Simulation 50-22 - cannot set manual registration using Simulation 50-20.
Cause:	Check the BK Image Magnification Ratio adjustment using Sim 50-10 and ensure the "inside dimension" for Main Scan is 240mm. If the set value for A (Sim 50-10) is higher than normal (eg. 116), change the value back to 100 and then re-execute Sim 50-22. good luck