HP 6030 mfp faded colour

[Guy-1]

I have a colour HP6030 mfp that has got faded / washed out colours, all CMYK appear to be the same.

I have tried running a full calibration a couple of times & substituting the ITB,  the issue appears to the same

The only thing that I have found which may or may not affect the colour fade is the cyan and yellow drums are less than 15%

Has anyone else seen this issue, and if so how was it resolved

Thanks

[Repairatrooper]

There are a lot of possible caused but not seeing the print quality pages and knowing the general condition of the machine I am only guessing. What we deal with most often is units being used in dusty environments and the optics in the Laser image scanners getting polluted with dirt. This is most noticeable for the scanner closest to the fuser assembly as this is closest to all the intake fans that pull dirt into the machine. Remove the toner and drum and inspect the slit at the top of the cavity which is where the scanner window is, if you can see dust there then your only option is disassembly to remove the scanners for cleaning or replacement. 

Other causes are weak high voltage board or bad power supply.