Biz 451 blue line

[copyman]

Machine had a blue line, I cleaned print head with the wand, pulled corona cleaner in and out, did not help so I replaced the Cyan IU. About a month later there was a P6 & P21 code, the only way I was able to get rid of it was with a new cyan unit. Now one week later blue line is back! There has to be something else going on. I can't keep putting in $400 IU's !!! Any ideas would be greatly appreciated. THANK YOU !

[copyman]

anyone?

[EarthKmTech]

anyone?

on the underside of the IU you can see the drum charger, have a look in there and see if anything has contaminated it and the colour of it, if it aint cyan you know which IU is actually destroying that one.

ALSO if its developer abrasion on the drum thats causing the blue lines, it should be fairly obvious to work out where its coming from (probably the IU to its left) You will see evidence in the form of developer trails on top of the imaging units leading back to the prime suspect...

if the charge unit is clean and there is no developer tracking from other IUS i would be suspicious of HV contacts, HV1 board or PH unit.