Minolta CF3102 toner/image drum issue!

[CopyXpress]

I have a 3102 thats having some issues, and me nor my boss have been able to fix it. It prints fine in black and white, but on color copy it will have a section on it that has a yellow tinge to it, and then random cloudy looking yellow spots in different places on the page. We've tried differen't yellow IUs (my boss things all the IUs we tried are shot). I just took a yellow IU apart cleaned it really good, check the corona and the grid, made sure the cleaning blade was ok. It was slightly better after that, but its still has a weird yellow splotch. Im at a loss! Any advice in the right direction would be greatly appreciated. Thanks for reading.

[CopyXpress]

Blah, this is driving me nuts. I got it to the point now where theres just a few random yellow "clouds." But its still not all the way gone. Images are coming out ok now, but some spots will appear more yellow than the original. And in the white spots on the page these faint clouds are visible. Im still being trained, im only in my second week, I would really appreciate any help! Sorry to sound like a whiney newb, but I'm just eager to learn.

[nichjar]

Are you able to swap the IU's in these machines? ex swap the yellow with the black and then retest, if it is the yellow IU and not something else you'll find out that way

[random]

The print head is stuffed. Swap it with magenta to confirm.