kon/min bizhub 420

[willcoli]

Have you tried cleaning/replacing tcr sensor? If so then as i said, replace the developer tank complete

[nvram]

hi, pale copies on these macines is always down to the t/s unit being soiled, as a matter of course i always replace on a service, if the mylars are missing on the t/s this can cause the dev to dump.
also be sure to upgrade to version 31 firmware otherwise you will have the customer ringing you because there is a change the fixing unit message on the screen, version 31 allows you to reset the count,

[Bizhub]

Check the position of the grid, also the dev unit connectors. We have had dev dumps due to the grid being out of position. If you can't cure the problem then make sure you have original drums etc fitted to the machine and start again. But I bet you have either a grid short prob or a warped dev unit.
Good Luck

[jrf]

I had this problem once and had to replace charge corona to solve problem

[moonwalker3778]

yes replace charge corona assy and transfer corona assy at time for every 250k copies