Docucolor 242 ITB transfer belt duty cycle?

What is the duty cycle (how many prints) for the docucolor DC 242 ITB transfer belt before it needs to be replaced for optimal print quality?

What other parts or durables of the DC242 need to be serviced at certain intervals that are not customer replaceable units?

 

About 1.5 milion

 

2nd BTR roller and ITB cleaning blade may need replacement first.

BTRs (CMYK) 600K (1 count for letter, 2 for larger)
IBT Cleaner Assembly 300K (1 count for letter, 2 for larger)
2nd BTR 300K (1 count for letter, 2 for larger)

 

The IBT belt in practically all the docucolor models will run "forever" as long as no physical damage happens to it.

 

We've had to replace our 242 transfer belt twice now in 800,000 11x17 and 12x18 prints, or about every 400,000 or the equivalent of 800,000 letter size pages. We print kromekote c1s, xerox 20# bond, and accent opaque 12x18 mostly. Both times the issue that appeared was a number of dark thin streaks running in the long process direction where light shades and midtones got darker in the same color in the dark "streaks." At first I thought the cleaning blade was a culprit, but it seemed smooth and even even when replaced. It seems on our machine that around 800,000 letter equivalent sheets the belt gets just striated enough that some of the striations start to accumulate toner in these lines. I'm not sure what causes it.