Help! Kai! I have spot that doesn't image

Please HELP! We have developed a small spot approximately 3 millimeters in diameter that does not image on the 4th unit of our QM4-DI classic. It doesn't seem to matter what file we try to image, the spot is always in the same position of the plate. I have cleaned the laser lens and what puzzles me is if it was anything to do with the diode one would think that a line would not image the entire length of the plate, but this is not the case as the spot is an oval that does not image. Has anyone encountered this problem? and if so what causes it. Is it possible that there could be a problem with the plate material

I appreciate any suggestions.

Djicewolf

 

Are you positive the plate isn't imaging, or do you just have a bad spot on your blanket that has an oval area that is crushed?

 

There is a good possability that they are looking at the issue on the plate itself, as the have imaged different files.

 

Hi,

It could be the plate material but you would be very unlucky to have the same oval hole in the same place every time the material rolls round, unless it was a manufacturing fault. Have you tried a fresh roll ?

You could also try the dead diode program on that particular unit and diode just to eliminate that.

Also make sure the plate cylinder is clean and free of anything that could be sticking to the cylinder in that position.

Regards.

 

Sounds like you have something on the cylinder, under your plate material. Cut around the spot on the plate and clean cylinder then re-plate.

 

Re: Non Imaging Spot on Plate with 4th Unit

Thanks for the suggestions, I discovered it to be a piece of dry ink that somehow got under the plate material and elevated a spot on the plate which must have disturbed the focus length between the laser diode and the imaging area of the plate. Its working perfect now.

Thanks