Developer fall out

[ali.alhaj]

I have peoblem with pro 1357 printer the machine every 10k there is no quality and the developer fall out on the duplex .
My procedure :
-replece new developer.
-replace new devlopment unit from other machine.
-replace new drum.
and still ?
every parameter is ok.
whats wrong?

[Iowatech]

Is the machine level? Check with a carpenter's level on the platen glass.

[imaginemoko]

check transfer belt if not worn out replace if life due already and clean transfer bias roller or replace if its rusty.

[thecopycenter]

Check your developer seals to make sure they are not torn. this will leak developer.. are your images light? if so check your toner hopper on your developer..turn the white knobs if the bottom one is tight, empty it out, bang it on the ground lightly then vacuum out, replace the toner in the hopper then do a force toner....
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