Pixel pattern showing up on my prints

[gillje]

Hi there, I've got a problem with my masters,

this weird pixel pattern is starting to show up, it seems to separate parts of the print where its printing totally fine from parts where it doesn't seem to be putting down as much ink, and other smaller parts around the edge of the print that don't show up at all.

I hope that makes sense, I've scanned a couple examples from a test sheet of patterns I printed...





What causes this??

[joelsa12]

well a model number would help. there are bugs in the imaging system in each riso. if it has a flatbed scanner the image cable will cause this. the GR series were released with a cable that was later updated because they all eventually failed. i am assuming this is on a Riso. depending on model number, but I am thinking an image board.

[gillje]

Oh yeah, it's a riso rc6300.

[joelsa12]

well as you know that is a very old machine. i would start by making sure all connections from the scanner to the image board and the connecting for the image board to the thermal print head are good. i am pretty sure there are test modes in the RC series that will print out a test pattern, but it has been so long that i do not know what they are. if anyone out there knows these it would help. if you could go in to test mode and burn a test image and the pixels are still there then the issue will be the image board or connecting to the thermal print head. if they are not then i would point to the scanner or connections from the scanner to the image board. sorry i have no test modes it has been years.

[gillje]

great thanks for the tips, I ran a test pattern and the pixels didn't show up.