C451 Weak printing/Spotty/blotchy

I have a C451 Copier that when it prints, only magenta seems to print correctly, black is very very weak and is spotty and smearing, cyan seems weak but is printing, yellow is printing but is also weak.

Not sure where to start, I tried cleaning the unit, cleaning the image drums, cleaned the charge wires via the built in cleaners, tried a half print and looked at the paper before the fuse and found it to be bad before that so I'm down to either the printhead, image units, powersupply, or something I'm not thinking of. I have another problem with it but this comes first.