Epilog Helix 40w raster roblem

[Ivica Vasic]

I have a problem with my Epilog Helix 40w 18x24
While doing raster picture or anything like that it makes lines ! What is the problem?

[img=http://s18.postimg.org/3yen1w8mt/image.jpg]
(http://postimg.org/image/3yen1w8mt/)
I forgot to add i have replaced old original lens with new Chinese because it started to make this lines but it didin't changed anything!
But when i work on 600dpi it works good!! Les than that it works like on the picture!

[Bert Kemp]

Hard to tell but kinda looks like banding. Do a forum search on Banding it might help. Could be other things also.
I would do a complete alignment, clean lens and mirrors and check for loose belts and or mirrors.

[Ivica Vasic]

thank you very much for the reply!

[Ivica Vasic]

i just have one question more... do you know the best way to do a nivelation of linear rods because i had a problem when i wanted to do align laser beam! if i align 1st, 2nd and 3rd point i couldnt make the 4th because laser beam is way off target! Somehow i manage to make it work ..So i found out that my linear rods are not in level! Do i use laser level or a bubble level or something else!
there is not much experts here! :)
Thank you again!