Need help calibrating topsetter 74

[vance]

Hello everyone,

I am trying to calibrate our topsetter 74 CTP, we are getting lines on the prints on the 45 angle and a deformed dot shape.

This happend after the tech person changed two diodes.

We are using sonora xtra3.

I am following the user manual.

When I screen the focus and zoom test plates, the pattern is not the same as the manual. Do I need to select the pattern before running the screen?

I cant find any prints, but will post here the plate and pattern from manual.

The black patches are 100% density and cant see any lines or dot densities.

I will post some photos here to explain.

Any help here very appreciated.

 

[vance]

Here is a test print. The dot shape is deformed.

 

[maxon]

It's not about calibration, but repair ... smth went bad during the laser diode replacements.
- put the sonora plates aside and run all tests on positive plates (process by hand if needed) so you get proper contrast exposed images
- run a grid test pattern to determine if H or V lines are corrupt so we can better understand what's going on
- find a USB microscope or take pictures through a macro lens and post the results here
- search all non-printing areas carefully for stray pixels.
One last thing, having seen the pictures attached I believe you didn't quite understand how to correctly set values in there ... I'm talking about initial and count values. Your exposure parameters are not right.

 

[vance]

Hello Maxon,

I will try that tomorrow and post results.

Could you advise how to set the values? I imagine you mean the set value in brackets?...I understood from the manual that it doesnt effect that tests. Its a Low value and a high value.

 

[maxon]

I've sent you a message

 

[vance]

I dont have any positive plates at hand. I will try to get some from a neighbour.

Here is a few more tests of all colors.