2901 uniformity headache

[Carlos Mayer]

Hi Folks!

I need a technician or a psychiatrist help. One of my 2901 doesn't finish the uniformity process (6088-0006 error appears at the end or almost end of the bar advance).

We did almost everything and always the results were the same.

- We installed several back-ups.

- We reinstalled the entire software and registering papers and magazines from the very beginning.

- We formated the PC and reinstalled everything starting with Windows.

- We exchanged transiently the PCs with another taken from another 2901 printer which was working well on its own printer.

- We checked the MLVA lamp power supply setting it as the another 2901 is: 27.7 volts.

- We checked connections between the PCI-LVDS conversion PCB and the Image Processing PCB.

The problem looks not to be inside the PC nor with the software (K version) nor with the operator procedures.

I'm ready to get crazy, please HELP!

Regards,

Carlos Mayer

[Dave S]

Try cleaning the integrator, that is the part where the MLVA fibre optic cable connects to the bottom of the filter wheel.

If it is very dirty, this will reduce the amount of light getting to the MLVA head.

How does the uniformity actually look?

Are there fine lines over the entire width of the head or is there a bad line in a certain place.

Scan in a 305mm width grey print if you can so we can see your problem.

[Carlos Mayer]

Hi Dave

Thank you very much for your answer! We did what you suggested, anyway

it was not too dirty.

I printed a photoshop 50% gray print, scanned it and published it at

www.revelados.com.ar/2901 for account space reasons.

Please watch it; this is the result of almost two

months without unifirmity process.

Carlos is out of the city for some days so I am writting, sorry for my

english!

Thank you very much for your help.

Edgardo Mayer

[Dave S]

The uniformity does not look too bad, there are no severe lines indicating a possible MLVA head problem.

I would say the problem is more related to the calibrator.

Possibly the reading surface of the calibrator is dirty.

Check that the calibrator moves smoothly across the head, if necessary lightly oil the worm drive.

Check the ribbon cable connection for the calibrator is ok.

Check the gain value for the calibrator in service mode; go to Menu, Extension, Maintenance, Various Adjustment, Printer Mechanical Adjustment, Gain adjustment. It should be between 0 and 255. If all are showing 0 or 255 there is definitely a problem.

If you press yes, it will check the gain values, and show you the before and after figures.

If the figures are abnormal perform a load voltage adjustment, go to Menu, Extension, Setup, MLVA setup, Paper

Specification Registration/Setup, Functions, Load Voltage adjustment.

[Carlos Mayer]

Hi Dave

- The calibrator was cleaned and it moves correctly.

- I execute gain adjustment and load voltage adjustment. Attach image.

I was the same problem...

I am thinking about changing the calibrator, ribbon and PCB card(J390566)whith another 2901. Each at a time. what do you think?

Do you have another idea? Thank you very much. I really appretiate your help.

Edgardo

[tj]

I have same error 6088-0006 uniformity problem .

I changed calibrtor relay PCB,ppp data out put PCB,drive voltage PCB and pre amplifier PCB.

All those were not effective.What if  that error message shows MLVA head itself?

what ever you do, Nothing's gonna change .This is my guess and I still suffering with same problem.

[mike11918]

Have you tried changing the lamphouse bulb? I have come across a good share of uniformity problems and several were easily solved by simply changing the lamp. Good luck. Filter wheel could also be bad.

[Carlos Mayer]

Hi again...

Since we have several 2901, we can exchange electronic cards. We did it exchanging the Computer, the drive voltage PCB, the data output PCB, the calibration sensor head and the calibrator connecting PCB but the problem persists.

According to the service manual (page 4653) these, as the image processing PCB and the printer control PCB, may cause the problem. Now we will exchange these two electronic cards with another ones that are working well. Since those cards have memories with info strictly related with the own printer, firstly we preferred to exchange the described cards in the first paragraph.

Of course, may be the MLVA engine in itself but I highly doubt it because there is no another evidence of printer function.

Answering Mike, the problem continues no matter which lamp we use, we tried with at least three diferent lamps with no good results.

Filter wheel? the manual doesn't tell that it may cause the problem but we could exchange it, too. It will take more time, we will do it and then tell you.

I technician from Noritsu Mexico suggested me to make a new uniformity pattern using a flatbed scanner but we haven't such scanner nor the corresponding masks. What do you think?

Just a minor (minor?) detail to comment: after we exchange one PCB, we could complete the uniformity process with only one paper type. We couldn't repeat this experience again nor could do the same with the other paper type.

Just to discard the exchanged PCBs, all cards from the bad 2901 are now being used by other 2901 which is working well, as before the exchange processes were done.

I will tell you what happen after we exchange the large PCB, this will be done in 3-4 days, sure.

Thanks for the support!

Carlos