C360 is leaving black stain on Cardstock not on Plain Paper

Hi guys!
Please what can be wrong?
Please help my konica c360 is leaving stain on Cardstock but not on Plain Paper, then if its to print a white it will have black stain on the front and back of Cardstock but no such thing with plain paper

 

Are you telling the printer that you're loading heavier stock? On the touch panel, you need to indicate the weight of the stock that you're loading. Look in the package of the ream of paper and it will say something like 176 GSM or 176g/m² on the label. Then, as you press Thick 1, or Thick 2, you'll see a range of numbers appear in the corner of the touch screen. If you are already doing this and you're still getting marks, you probably need to have a service call done to get something cleaned/replaced.

 

@jwheeler yes am selecting the card thickness I will send the sample of what is coming up tomorrow.
Thanks

 

This is what am getting @jwheeler

 

Now the latest issue is that it leaves stain on Plain Paper too

I will appreciate if someone can help me
Thanks in advance

 

Looks like you need to change out the cleaning blade and transfer belt. Put in a service call.

 

Oh okay thanks @jwheeler