Hamada 234 C tinted bars appearing

[WPC1]

Long time reader, first post. I'm running a Hamada 234 C with Crestline dampeners. Lately I've developed 2 tinted bars running across the plate cylinder and then, of course, the blanket. They're about 3/4 to 1 inch wide. One bar is right on the gripper and the other is about 12 inches down the sheet. Roller pressures seem to be ok and I've been using the same fountain solution forever. Any ideas what this could be and what to try?

 

[SteveSuffRIT]

When problem solving and troubleshooting, conduct simple tests/experiments to isolate and identify the root cause. The this or that test are based on what it possibly could be, plate, rollers, etc.
For example, if you rotate the plate 180 degrees, does tint band stay in same location or move?
Is "Tint" band/streak from the plate being drier in that location? To verify, dip your finger into fountain solution and touch the dirty area on the plate, does it push the ink aside and become clean?
Is it happening on both units, or just one?

 

[seanryder]

Check the ink form roller stripes to their adjacent oscillator rollers in the ink train. I've found that as rollers shrink they can slip while running. Even though there may be a good stripe to plate if the roller is slipping on the oscillator roller due to shrinkage you'll get wide bands like that. I'm not familiar with Hamada but on our Ryobi 3302 and 3304s I've seen it. Try turning off the third (lower) ink form roller and run to see if the band 12 inches down goes away. Hope you work it out.