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Techead42
01-09-2009, 12:55 AM
We've been struggling with a CS650 color change issue...customer runs a print job with gray background & background progressively fills with magenta till the original color is no longer recognizable. Internal test prints look fine (#53, each color, about 40%). Any thoughts?

knightfall
01-10-2009, 01:21 PM
do you have the latest firmware installed? 3 color gray are usually the hardest to maintain consistent you may want to see if the customer is willing to use black to make gray instead of 3 colors.

Setright
01-11-2009, 06:46 AM
Using K only will make for quite a rough resolution, so often the customer insists on mix :)

I have been through this with a number of our proffessional customers. Magenta has a tendency to come forward in standard flourescent lighting, so make sure you review the samples in the expected viewing light.

Which controller are you using? Fiery calibration via ES-1000 produces some very nice graphs that can help you analyse the health of the gamma sensor. If M,Y, and C drop off and level out, the gamma sensor is busted.
(Creo controllers reject the calibration for not meeting targets.)

Have you set the gray balance using the manual gamma offset adjustment in the quality part of the service menu?

There is also a dipswitch setting to force the engine to run it's automatic gamma sensor adjustment every 400 prints, this will help a lot. The standard setup will only start the process between jobs, and only if the preceeding job clicked past 400 prints, which means a job with 1000 pages won't get an adjustment and the gray mix will show this up really quick! (Can't remember the switches by heart, but I seem to recall it's 23 and 24 you need to look up)

You may be able to gain some added consistency by using another screen. Dot1 is great for detailed pictures, but large areas with a low coverage can suffer lines and moiré. Try Line1 og Line2 - and make sure you set their gray balance first. (Dot2 and Line2 have two settings, Type1 and Type2. The latter is quite coarse but is perfect for light colours with big surfaces)


Finally, is the primary transfer system clean and polished?

random
01-12-2009, 07:48 AM
Have you set the gray balance using the manual gamma offset adjustment in the quality part of the service menu?


This is pretty critical and often overlooked so I suggest you go thru this procedure with a fine tooth comb. Unlike the c500 the offset adjustments do have an effect on printing.

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