panasonic 7735 toner droppings

[lowrider]

Im quiet familiar with the Fp 7718 , then I got a 7735 i noticed that there is a return system for the toner of the 7735, my main problem is that I have excessive droppings on toner on both sides of the paper ( both sides of the drum), is the drum unit interchangable with the 7718 without the return system?, on thing I also noticed is that when i got the machine the solenoid of the return system was disconnected and and taped, should i plug back the return solenoid? and whats causing all the excessive droppings? thanks

[Guyser102]

The toner re-cycle system on the CF-series machines was implemented to extend the life of the toner. Of the 6 models released, the FP7728,7735,7742 and 7750 had the recycle system. The FP7718 and 7722 did not have the toner recycling system.
In instances of high temperature/humidity, excessive toner fluff etc.. the copy quality was compromised because of the recycling system. Therefore many field engineers disconnected the recycle solenoid to prevent recycling which caused over-toning and hence toner dumping from the dev tank and poor copy quality issues. Personally, I do not use this method. When faced with this sort of issue, I replace the developer and set F5-65 to 0 i.e refresh the toner every 500 copies. Important note is to empty the recycle coil of any toner before you perform TDC adjustment. If any toner is left in the coil, it would be fed back to the dev tank and compromise the TDC values. This worked well for me on those Analogue copiers. Dont see them any more, but enjoyed their reliability.
Regards,

[lowrider]

thanks you so much guyser for clarifying the issue, it was really pumping in too much toner from the recycling tube, more back than to waste, now that i know the reason ill just get familiarize with the system and adjust on how to compromise with it, does the tdc sensor also has something to do with the switching of the return solenoid? or it switches by the number of copies

[Guyser102]

Hello Lowrider,
The toner refresh cycle is determined by the F5-65 setting:
0 = 500 copies refresh cycle
1= 1000 copies refresh cycle
2 = 1500 copies refresh cycle
3 = 2000 copies refresh cycle
I believe the correct operation is as follows: If F5-65 = 0, then for 500 copies the solenoid will be in the recycle position (no fresh toner). At 500 copies, the solenoid will engage to the refresh position (fresh toner for 200 copies) and then followed by recycle again for 500 copies. the idea of setting to the lowest refresh cycle is to get fresh toner in as often as possible.
Regards,

[lowrider]

thanks for that info guyser, your the ultimate panasonic guru, that really helped ! thanks

[IfItAintBrokeIcantFixIt]

One more thing you may want to take a look at for toner dropping is the lower toner support in the cleaning section. This is the mylar sheet below the cleaner blade and in front on the cleaner section return spring. We still have quite a few Medialion series machines in the field (They wont die) But do to age these mylar supports get deformed and cause machine to drop toner. Its a mylar guide that is attatched to a metal plate that is held on with three screws, you will see what I'm talking about when you see it. But it should be striaght to catch excess toner as scraped off by cleaner blade. I bet yours is not straight.

if you don't have one it is even possible to repiar this untill you can get one buy using scotch tape to pull it back out to wear it will catch toner.

Hope this helps

[lowrider]

thanks very much for that info, Im servicing several units and i noticed that on some units the mylars are wide (almost touching the blade) , some units the mylars are narrower, the ones with wide mylars are the ones that drop toners, its kind of difficlut to remove the mylar assembly so what i do is i use a cutter knife to cut it and make it narrower , usually this solves the problem, could this be right? or i should just reinforce it with scotch tape as you mentioned?-thanks

[IfItAintBrokeIcantFixIt]

thanks very much for that info, Im servicing several units and i noticed that on some units the mylars are wide (almost touching the blade) , some units the mylars are narrower, the ones with wide mylars are the ones that drop toners, its kind of difficlut to remove the mylar assembly so what i do is i use a cutter knife to cut it and make it narrower , usually this solves the problem, could this be right? or i should just reinforce it with scotch tape as you mentioned?-thanks

No don't cut it, that will make the problem worse. and yes getting the whole thing off is a pain-is has double stick tape behind it. The best solution is to replace it. second best it to use the scotch tape. if you aplly the scotch tape right on the outside of the mylar and pull the mylar out to meet the tape it works pretty good. But like I said it best to replace it

[tseto]

Im quiet familiar with the Fp 7718 , then I got a 7735 i noticed that there is a return system for the toner of the 7735, my main problem is that I have excessive droppings on toner on both sides of the paper ( both sides of the drum), is the drum unit interchangable with the 7718 without the return system?, on thing I also noticed is that when i got the machine the solenoid of the return system was disconnected and and taped, should i plug back the return solenoid? and whats causing all the excessive droppings? thanks

change the toner support, the rubber recovery film opposite opposite the cleaning blade. the film is warped and not catching the toner cleaned off by the cleaning blade.

[lowrider]

thanks tseto, and to everyone who was very helpful, with all your help i was able to find the fault and correct the problem, at first I really did not thought such a small sheet of rubber could clean that much toner, upon close inspection on several machines i now know what the correct position should be, thanks to all the gurus