mx-c401 cyan misregistered

[tmw]

We are now having to chase down ideas for this thing. It started printing what looked like color fringing on the rear side of the print. Our other tech was the first to look at it. He tried running the sim 50-20 & 22 & adjusting the laser skew screws. Nothing changed much besides variations in the degree of misregistration. The sim values would also change all over the place. He then went back & put in a new primary transfer belt assy, different 2nd trans., tied different drums,main board, & scanner board which had no effect.
I went there to take a shot at it with a different drum drive assy. When that didn't change anything, I tried updating firmware, and more drum swapping. I also was trying the same sim & screw adjustments with the same luck as stated above. After some variation, it seemed to consistently settle on the cyan being 1/32 inch out of plane.
Now we are trying to figure out why cyan and why it would change at all. I tend to think it might be clutch related being intermittant like, but which one ? We're running out of parts to try. Next we will go back with a transfer belt reading sensor, and a small gear train with a clutch that drives it. After this I don't know where to go. I wonder if anyone else has had such a stubborn issue. As always, thanks for your consideration.

[Phil B.]

We are now having to chase down ideas for this thing. It started printing what looked like color fringing on the rear side of the print. Our other tech was the first to look at it. He tried running the sim 50-20 & 22 & adjusting the laser skew screws. Nothing changed much besides variations in the degree of misregistration. The sim values would also change all over the place. He then went back & put in a new primary transfer belt assy, different 2nd trans., tied different drums,main board, & scanner board which had no effect.
I went there to take a shot at it with a different drum drive assy. When that didn't change anything, I tried updating firmware, and more drum swapping. I also was trying the same sim & screw adjustments with the same luck as stated above. After some variation, it seemed to consistently settle on the cyan being 1/32 inch out of plane.
Now we are trying to figure out why cyan and why it would change at all. I tend to think it might be clutch related being intermittant like, but which one ? We're running out of parts to try. Next we will go back with a transfer belt reading sensor, and a small gear train with a clutch that drives it. After this I don't know where to go. I wonder if anyone else has had such a stubborn issue. As always, thanks for your consideration.

Is there no auto color registration adjust?
Turning screws is for when the ROS/Laser is swapped out... from your notes that wasn't done?

[mansart]

I would try a new LSU, or swap from a working machine to test.

[copiertec]

I have had issues with drum phase adjustment (50-22) caused by bad primary transfer units or fuser units binding up, but I see you have swapped transfer units. Assuming you have done all the color calibration procedures, prior to your 50-22, I would make sure your sim 50-20 is all at 100 (factory defaults), which seems to have been done. If all of that fails, before you swap drive sections and or clutches, swap out the laser unit, as it is easier than swapping drive sections.

[tmw]

Thank you for your replies. I forgot to mention that the laser has been tried as well. The auto adjustments and the 50-20 defaults were tried also. Nothing much changing so far.

[mansart]

Do a SIM 64. Print out a PCL test and a PS test.

Scan and post the results.

[fireater]

only thing left would be image quality sensors

[Phil B.]

only thing left would be image quality sensors

quality sensors? you do mean REGISTRATION sensors?

[tmw]

Sorry to report no more luck. Tried last part left, registration/quality sensors and the unit that drives it. No change. Will be replacing machine.

[repn1999]

I would suggest changing out the main drive unit. I have seen one several different series of smaller sharp color machines where random gears get some play in them or broken/worn teeth and cause strange issues. That is also where the pri trans clutches(there are 2) are so that will rule them out also. next you may want to look closely at the frame part that holds the drums and dv units. I have seen the catch get deformed or broken and then the drum or dv unit does not sit securely in place and will cause strange registration issues. i have actually proven this by cheating the front door and pushing on the units on some machines or putting a piece of paper folded in a small square on the front of the suspect units and letting the waste container push it in for me if i cant get to it with the waste container in the machine. Also I would play close attention to the transfer belt itself and would highly suggest buying a new unit from sharp. There have been extensive mods to the older units and I believe the older units cannot be modded to be like a new one due to design changes. be sure to use the belt setting powder as stated in tech bulletin. Lastly I have attached a bulletin with a mod that I have personally seen cause strange issues with this series of machines, so maybe it is the cause here. I personally think these smaller machines are more headache than they are worth and we pretty much upgraded all of ours to mx2615/2640s or newer which seem way more reliable. Hope this helps