Konica 4145 - Error J21

[century]

Hello all,
I have a problem with Konica 4145 paper jam (J21). After I change new Drum and Cleaning blade, put it back and turn on then it give me J21 (paper jam) . But I had look every where and there is no paper jam. Please tell me beside paper jam is there any thing else for J21.
Also, I am looking for service and part manual for this copier. If anyone can share with me please send to mr2lp@yahoo.com
Thanks

[dogsbody]

Did you remove a green coloured genuine drum and replace it with a non-Konica drum of a different colour?
This takes me back but we used to use Katun drums in these machines which were a reddy colour instead of green. The different colour causes the jam sensor to read incorrectly and display a jam (J21 Drum Wrap Jam).
With the drum removed under the cleaning blade in the centre there is a photo sensor, you will see three parts to it if you look closely, the two outside are for reading the toner patch the centre is a jam sensor. If the drum you are using is not original it should have come with a filter to stick over the centre jam sensor if not cut up a small piece of BLACK (must be black) electrical tape and place it over the centre, make sure you only cover the centre otherwise it won't feed toner.
Good Luck.

[century]

Hello Dogsbody, I think you was right. I use non-Konica drum and it's kind of reddy colour. I will try tomorow as you said, hopefully they didn't throw the Drum's box. Thanks

[bushy]

konica 7033 j21

make sure the drive collar is engaged at the front of the drum
its the drive lug that you retract when removing the drum if it is not located into the front of the drum you will get no drive to the drum thus j21

good luck

bushy

[bushy]

4145 j21

after market drums need a green filter in front of the jam sensor to adjust for the different drum color
katun usually supply this filter with their drums

bushy

[century]

OK, I did try on 2 konica 2028 and 4145. The konica 2028 is work fine with this trick. But the konica 4145 is still show J21? I try to remove the black sticker off the jam sensor and put the old OEM drum back then is ok. Do you have any idea why? Thanks

[dogsbody]

OK, I did try on 2 konica 2028 and 4145. The konica 2028 is work fine with this trick. But the konica 4145 is still show J21? I try to remove the black sticker off the jam sensor and put the old OEM drum back then is ok. Do you have any idea why? Thanks

the two drum units will be very similar but they are different, you will notice that the 2028 unit does not have the middle jam sensor for drum wrap (only has the patch sensor and so does not need the mod applied) and also only has plugs on the back end of the charge corona, the 4145 will have a conector on the front as well as the extra sensor for jam detection.
I came acoss Katun (Red Drum with blue filter) and Celcast (yellow drum with black tape) drums. The katun filter still allowed the jam detection to work, they supplied two filters, sometimes it required both filters be applied. The Celcast method was to cover the sensor with black tape tricking it into thinking that it was clear - even if it was not.
If it works with the genuine drum then the filter is not being applied properly when the new drum is being unstalled.