km2550 almost blank

[Iman]

Hi all I'm having a problem with a km2550.The machine was due a full maintenance kit due to copy quality but this was just due to a worn drum and milage.When the kit was changed the dev gave me a NG message and the image was over-tonned.After a short amount of copies the image faded almost completly apart from two inches from the edge of the copy.So far the copy kit has been replaced and all units exchanged with know working units i.e. drum and dev.I also changed the e.c.b and high voltage board along with the lazer unit and so far no joy.Has anybody experianced anything like this.Any info would be much appreciated.

Thanks.

[Tech59]

Q: did you replace the Maintenance Kit MK-420? because the Drum and all normal PM parts are due for replacement at 300K prints for the KM-2550. What kind of Copy Quality issues were you having before?
I would start by (1) making absolutely sure that you Have replaced the correct items for the machine is question. The KM-2050 and the KM-2550 are different components. (2) make absolutely sure that you have connected all the connecters to the Developer unit and the Drum unit connected. (3) Check the Transfer Roller assembly and make sure that everything there is Okay.

[taskalfaman]

hi technician,
problem probably due to one of the first machines.
First check if you do sim 130 if toner motor turns8
if not; steps to take;
update the machine
change engine pcb and toner motor at the same time.
run SIm 130.
problem should be solved.
there is a very old SB for this issue.
have fun.

[Iman]

Hi thanks for the reply but as i said i changed the full maintenance kit and also checked those units by using known working units from another km2550.I also changed the ecb-engine control board and the high voltage board.The dev unit is being driven and is loading toner. The image is only on the first two inches (side to side) of the copy ,it is not light all over. Anybody seen this before

[taskalfaman]

did you check the tr roller?

[Iman]

I ran copies with the side door open and could see the image on the drum.The image on the drum was the same as what is produced on the copy so it leads me to think that it is not a problem with the image being transfered from the drum but with the image being placed onto the drum ie. either drum or dev charging or a board problem.

[aodtech]

I'll break it down this way. The High Voltage Board supplies the Transfer, Separation, Main Charge and Developing Charge. Between the actual components and the board you have these flat, thin terminals. They are mounted on a cheap plastic base. An opening on the terminals mounts on a small nub on the base which can be easily broken. What I had experienced before was the plastic nub on the TS broke, letting the terminals float and giving me light copies. The Transfer/Sep has one base and the DV/MC has one also. Remove the HV board and make sure that none of those terminals are floating. Also check from the other end too. And just for the hell of it, check the TS also.

[Iman]

Thanks for the reply aodtech I'm familiar with the process and I have checked the contacts and even replaced the housing in case of arcing. The problem I am having is not light copies but only partial copies.There is an image on the first inch or two of the page then the rest is blank.
Thanks again

[Tech59]

Have you checked to see if the Developer Roller is Turing or better yet make sure that all the rotating components of the Dev Unit are turning and verify that the Dev Unit is rotating while the machine is maks a Copy or a Print.

[Frits]

Maby this wil help you Make sure that you isolated the top of the terminal base see bullitin

[jewen25]

Thanks for the reply aodtech I'm familiar with the process and I have checked the contacts and even replaced the housing in case of arcing. The problem I am having is not light copies but only partial copies.There is an image on the first inch or two of the page then the rest is blank.
Thanks again

try sim 000 print report? if it is not ok,try to check the scanner flex connected to main board maybe have a slight scartch or replace the flex,if its not ok concentrate in optical/scanner area of this machine i think the problem is there