same problem for me... old topic but i think can be good the same, so:
the printer stored for years, can damage a little the trasferring drums (thin crushing along the surface of the trasferring drums due a pressing by the trasferring belt system);
if the trasferring belt presents, after a printing, residual of thin lines of toner on it, then is good to try to follow these steps:
WEAR BREATH PROTECTION, GOGGLES AND GLOVES FIRST!
1) deep cleaning of transferring drums unit:
carefully, do it using compressed air avoid too strong pressure and keeping it far from light (otherwise it will be damaged), check if the recovery boxes in the rear are not clogged;
2) clean carefully the trasferring belt, check for integrity looking it backlight; remembver that also the belt is light sensitive, so don't put in the direct light for more than 5 minutes
3) clean the optical system (it is located just in the rear of trasferring drum unit, after remove it you can see oblung loopholes that is possible to clean using cotton wrapped around a stick
4) after 1,2 and 3, try also to leave the accessing hatch slacked for some days, keeping covered the printer with a cloth;
on my printer, it worked almost perfect ( a little, thin and short line still there but almost invisible...)
hope to be useful.... gretings to all!
