7155 toner dump drum wear

[Paperboy]

Hi
I have a 7155, it is continuously dumping toner and developer onto the corona wire, the drum is also wearing really badly, I have done a number of things so far to try and resolve this:
replace the drum (duh)
replace the corona wire
replace the corona transefer separation plate
replace the LED light strip below

problem is that it has gone 5 times now, and gone from normal to lasting 3 weeks and last time down to 3 days.

Has anyone encountered this if so did you find a solution?

Thanks

[ebm]

This is common for this model. All you can do is replace the developer and hope for the best. You can try adjusting the 25 mode dipsw's that control toner density. But even this sometimes does no good. Konica claims that paper dust is contaminating the developer unit when the toner is recycled. If this is so, why do they insist on recycling toner?
Anyway, good luck!

[Paperboy]

thanks I tried that too forgot to list it, but did no good, hence i got the bizhub just need to get it printing right

[superfly]

I suggest replacing the whole trans/sep unit, or maybe replacing the pm kit, which has the drum cleaning roller, blade, web, filters, and all wires. i usually start noticing that around 300K and a good cleaning of the drum unit takes care of it until 500K (PM time). CQ looks great if you do pm kit drum and developer at the same time. that also lasts the longest. now, if the drum is worn down to the aluminum an the edges, i would definately look at replacing the tran/sep assy. or make sure that the charge grid is seated correctly on the unit. Dont forget to clear the counts n run adjustments in 36 mode.
GOOD LUCK!!!!!

[bgbas]

Here is a fix that works.

[random]

Everyone seems to hate these machines but I have not had a bad run with them personally. In fact we chuck on an extra 100k on the kit time. So lets think why this machine might be a dog in your situation.

1. Temperature - Is the environment too hot or too cold?

2. Humidity - Too high? Too low? (check in 47 mode)

3. High coverage?

3. Low coverage?

4. Media? Some papers are super dusty.

5. Dip-sw's change cq switches all back to factory.

As superfly says replace everything at once, changing only the drum and and devs is throwing good money after bad.

This should include, tran/sep wires (clean unit with water and a cloth), cleaning blocks, charge wires and cleaning blocks (clean unit with water and a cloth) , drum, dev, blade, toner collection roller, suction filter. Blast the whole drum unit with some air and make sure all the sensors are clean.

Make sure the glass between the write unit and the drum cavity is clean.

These machines dump but if you are meticulous when you service them they will behave but you need to put the time in to get the results.

The only ones that don't dump are possibly the 600/700 but that is only because they have soo much suction to get the crap out.

[peter lynn]

7155 dumping

Hi
I have a 7155, it is continuously dumping toner and developer onto the corona wire, the drum is also wearing really badly, I have done a number of things so far to try and resolve this:
replace the drum (duh)
replace the corona wire
replace the corona transefer separation plate
replace the LED light strip below

problem is that it has gone 5 times now, and gone from normal to lasting 3 weeks and last time down to 3 days.

Has anyone encountered this if so did you find a solution?

Thanks

the drum wears on yhe front end?,and picks off dev material and contaminate coronas/fixer? its the charge grid cleaner pushing the gri on to the drum ANSWER....throw away grid cleaner and mybe also cut back grid end supports by 1mm/1.5mm.then fit new grid /wires etc .this has worked on100+ machines so far AOK.happy copying peter

[bgbas]

Random, the 600/750s dump also.

[random]

hmmmm, well this product is dead now anyway. From what I gather the 920 is the slowest b&w konica will be making from now on.

[peter lynn]

7155thro7272 an600 /750 all the same

Random, the 600/750s dump also.

only real difference in their makeup is toner in the bizhub
they cannot be ignored when i have about 400 of them to get thro the day.but what i said about the grid cleaner pushing the grid on to the front of the drum also goes for the bizhub600/ 750,and of course doing a full srevice on time . every one dumping is over life on service items,too many tech ,s trying for the easy out! much obliged peter

[CMB]

a quick fix that we are doing now is taking a paper clip and tieing it on between the mag roller(big c-clip) and the screw just below it. we found there was not enough bias to start with. this mod is a better bias connection to the mag roller and we have not had this problem since we started doing this. if you check the bias on the mag roller it should drop down to zero. also go to dipswitches 1-0,set to zero,1-1,set to zero,1-2,set to zero and 1-3,set to 1. this shuts the copier down when it runs out of toner in the toner hopper. we found customers are not replacing the toner bottles when the copier ask.

[Dougall]

7155 toner dump

Random could you answer this question?

2. Humidity - Too high? Too low? (check in 47 mode)
What shoul the right humidity be?

3. High coverage?
Whats high coverage mean?

3. Low coverage?
Idem?
I have a dificult with my english
Thank you

[redhotrob]

Grid Voltage

Don't forget to set your grid voltage using a good meter. I've seen others using cheap meters that measured 30-40 volts differently then mine. This will make a difference over time.

[Haroldbfix]

Also try this in addtition to setting 23-2=0, 23-3=1, 27-0=1
Make sure all other dispwitches are set to spec.
set LD1 &LD2 offset to spec then do all the drum pecularity adjustment.

I have around 100 of the B600-7255 all run clean. This procedure will reduce the spill by about 80%

[Two Medicine]

CMB has the experience on this. Konica had at least two bulletins out on this problem and they revolved around a dev bias issue. They recommended a flat spring installation to the mag roller to improve bias contact, but on some units all you could do was replace the developer unit. Once the dev assy was replaced you were good for another 300K to 500K before the machine exhibited the problem again. We've used paper clips and braided wire in a pinch. Konica came out with a list of about 15 things to check for. If you have access to their bulletins and tech notes you should be able to find the list.