HP LaserJet Color 1600 print scratches

Hi,
I'm using a HP Color LaserJet 1600
Someday the cyan and yellow start printing dirty like scratches which can't be cleaned.
The toner has been refilled.
Can it be fixed ? or is it time to replace the toner ?
Thanks

if its just these 2 colours, check the drum on each one to see if there are marks on it in the same place. these are usually where scratches occur. refilled toner is never as clean as originals and maybe the cleaning blade on the drum units need cleaning..

Thanks for your reply.
I believe it's the cleaning blade, where is the cleaning blade ?

take out the drum unit, there should be a cog on one end, turn it one way and you will see the blade is just a piece of plastic that runs the length of the drum, turn it slighly the other way and the drum comes dirty from toner.. thats the blade. when you turn it the correct way the drum should be free from toner and you may see marks on the drum that correspond to the scratches. you may need new drums if this is the case