RISO (RZ 990U) White lines on print problem

[patefilo]

Hello,

(My Riso level has to been considered as newbie )

I print from my computer an image and some white line appear on my print somehow. Here are a couple of photos of the master first:
Master01.jpg
Master02.jpg

And a photo of the result on the print:

Print01.jpg

Do you think it's a problem of ink, master making, drum, settings...?
Thanks!

[VENRISO]

hello, by the problem I think it is ground, you should try using the scanner of the machine to discard it RISO, you must have some ground problem on a computer.

[VENRISO]

the problem of ink on the edges of the drum can be two things, one needs to change the pressure roller two need to change the screen assy

[patefilo]

Thanks for your answer VENRISO.

What do you mean by "ground"?
Also, what is a "screen assy"?

[jermyth]

It appears to me that the drum screen has gotten dry. Possibly even the drum body too. Ink is not getting to those "white" areas on the drum. The screen and I'd even suggest the drum body get cleaned. As to your next question what is the screen and what is the body; the screen is what your master is on top of and the body is under that. I strongly recommend getting a manual and parts books. As to how to clean them, alcohol or another solvent to break up the dried ink. Others have posted on how to do this better than I can say.
Good luck.

[patefilo]

Thank you jermyth! Sounds great. I'll keep you posted on the results, time for me to find alcohol and manual

[patefilo]

Ok. Everything is cleaned now with alcohol. Borders are now OK! Great. But unfortunately, I still white lines on my prints as you can see on the photo below.
20160616_170805.jpg

I downloaded the user manual which suggests me to clean the thermal head in that case. That's what I did but still the same

[VENRISO]

the ground can be a power cord that is damaged or defaced or any short circuit that is on the computer, so called peak voltage

[VENRISO]

the screen is silk or cloth covering the drum body is gray

[patefilo]

I finally managed to do something correct by cleaning the whole drum and doing other masters!