Konica 7255 Drum Wrap

[Downunder]

Peter, you mentioned drum voltages, earth etc. Have you done an earth from the screw that holds the drum in on the drum shaft and earth. Should be 5ohm or less or should be low resistance. If it is high check the drum clamp (slide drum onto the drum shaft, then holder, then knurled bit (sorry just cant think of correct words, late in the day and bourbon has kicked in) sometimes this clamp/stay gets a bit rusty and inhibits good earth through drum bearing. If this is clean and you still have high resistance you will need to go to back of copier, remove back cover and main board, then flywheel. On the the drum shaft there is a copper leaf-spring(spelling) that rests on a round spacer which rides on the drum shaft. If this leaf spring is not firmly touching the spacer you will not get good earth. Clean the spacer, it can get a bit greasy reform leaf-spring.

Is your registration constant? sorry, harping back to paper slippage again.

Clutching at straws now, but have you changed the ADU board. Weird faults with this board.

Hope this gets you a bit further to the client's EXIT door.

Cheers

[PeterG]

Thanks again Downunder. I think you are onto it. I measured the resistance on the drum. It is 800 ohm at minimum, & goes to over 15k.
I didn't have time to rectify it yesterday, will sort it next week.
Thanks again

[SAR]

Are you absolutely sure there is no developer in the drum picker solenoid? I have seen machines where you can watch the picker fingers working during a copy run, but when you pull the solenoid apart and clean it there is just enough developer in the solenoid to make it intermittantly malfunction or the plunger pulls in too slowly and the paper gets past the picker finger.