I have 4 machines at diff. locations that are going lite on the center or on one side of the mag roller. The copies of course are light in that area. I have to run sim. 130 usually twice.the quality comes back.OEM toner only.Two machines are in the same building.Task 820 and 6030. This may happen every 2 to 3 weeks.Any ideas ,thanks

Heavy fill copies and prints? Perhaps the toner feed just can't keep up with the usage.

Could happen but not on all 4 machines at once.Wondering if KM turned out some bad toner.

Check the spring that cleans the toner sensor in the dev unit. If it is not cleaning off the sensor it will not add toner to the dev unit properly.

Is the machine level? Also I recently had to replace a dev for light streaks. I could run 130 and it would clear up but would come back. hasn't come back since I replaced the dev.

Try Mark B idea. I had two of these machines both 820's that the spring wasn't touching the the toner sensor. Sim 130 would get them going again but the problem would come back. Replaced both dv units under warranty.

Thanks guys. Do you have to dump the developer out to set the spring? do you bend it?

Gently brush off toner from face of sensor and try to bend the wiper in place. Take your time with the wiper because it is a very thin piece of metal.