Screen 8600 Imaging Issues

[kev234]

We're having imaging issues with our Screen 1600, where we are getting uneven imaging thruout the plate. It will show up in flat screened areas as 'streaks', or uneven stepping. It's doing it on all of our various size plates, all different lot numbers. So it's not the plates themselves. We changed developer to see if it was bad, but we still have the same issues. I'm beginning to think it might be a laser problem on the screen itself. Anyone else ever run across this problem? Would love to get some input as we await a response from Screen. Thanks!

PS..I forgot to add that the machine is about 5 years old.

 

[KimSaks]

Sounds like you've lost your plate calibrations... zoom, focus etc. Has anyone been messing in the set-up or service panels?
If it were lasers going bad or the optics dirty enough to produce the problems you described the machine would likely pop up with errors.
Are you under a service contract or have a regular service provider? If not, give me a call or send me an e-mail I may be able to recommend a qualified technician.

Kim

[email protected]
702-561-5936

 

[nelly]

Problems I have had with our 2055 are;

dirty spinning mirror due to dust.

crud on the long lens leading to soft banding.

Both sorted by an engineer visit.

Edit: re below post from Blane.

I am on the 3rd scrub roller now, the glue that they use parts company with the steel roller over time at the edges eventually and the scrub material comes away and you can guess the rest.

Are these streaks or banding visible on the plate before it goes on the press Kev?

 

[59blane]

A couple of questions:

When you say streaks, is it like blotchy areas on the plate? Do they run the length of the plate? Are they generally in the same place on the plates?

First thing to do is to either eliminate the plate setter or the processor as the cause. Try imaging a plate and then turning it 90 degrees when putting it into the processor. If the streaks have changed direction on the plate (meaning if they were going the length of the plate and are now going across the plate in the same direction as travel through the processor), the processor is the cause. If this is the case, most likely cause would be your scrub roller needs to either be changed out or adjusted.

If the streaks are still in the same direction on the plate, I would then run an internal screen test from the machine itself to eliminate a communications issue from the RIP/Shooter. If the streaks are still present, I would have a Screen service engineer come in clean your optics and look at your power, focus and zoom settings. It may also be caused by uneven vacuum at the drum. But I'm betting it's the processor.

How long has it been since you've had a PM done on your processor and plate setter?

I hope this helps you find the issue.

 

[kev234]

Thanks for the replies everyone. The technician just left, and it was dirty optics. We don't have a maintenance agreement, so they only come out when we have in issue. And believe it or not, this was the first time everything was cleaned since we had the machine. And of course, the tech said it's not something we could do ourselves, so it looks like it could be a while before we have it done again. I really appreciate all the insight guys, this is a great place to get good info before we call someone out.