Mutoh XPJ-1682SR print defects

[TroutFarmer]

we get errant print defects showing up unpredictably. Have cleaned the T Fence and problem went away for a few weeks. Then we had re-seller do service on machine and they replaced TFence and sensor but the problem returned in two weeks. Replaced TFence and problem went away for 12 hours of printing then returned. Replaced TFence again and problem went away for a day but returned. So I got to thinking maybe it's the PF Encoder wheel or sensor. Cleaned those and it went away for an hour but returned. I noticed, though, that the PF Encoder wheel has some scratches from the small plastic guide pins, (not in sensor zone) AND a small dent along the edge at one spot on the wheel (within the sensor zone). Any advice?

 

[Solventinkjet]

Unfortunately, patterns like that tend to be electrical issues with the head signal circuit. It's very common for it to be intermittent like that. We usually start with taking a look at the head cables and replacing if damaged, dirty, or have corrosion on the silver leads. You weren't wrong to suspect the encoders but since the problem persists even with new encoders, it's more likely going to be a bad cable, head, or main board. I've never seen the print feed encoder do this but with these machines, anything can happen in the long run.