C364 Fading one side

[Guy Milner]

A problem that has stumped 2 Konica Minolta techs, with over 25 years experience each!

We have a C364 (non e) with fading black on one side. Colours are perfect though.

3434234343

See example (if the upload worked?)

If you want to suggest what could cause it, please let me know and I will let you know if we have tried it!

[mo0651]

What is feed direction?? We have seen Printheads do this.

[allan]

Had something that looks very similar.
Thanks to Hans i got it sorted. Was on a C360 with a bent laser glass cleaning rod.
Well no rod on this model but i would also say something is obscuring the laser from reaching the drum.

Only other thing i can think of would be primary transfer voltage not making it to the transfer roller in the ITB.
Bad contact on the machine side or the HV supplied?

[Guy Milner]

What is feed direction?? We have seen Printheads do this.

The second example is an A3 (127 halftone) test page, so that should answer the feed direction question. The fading is from middle to rear. Printhead is a good call. We had the unit out for a thorough clean, but as yet, not replaced it. Will update. Thanks.

[Guy Milner]

Had something that looks very similar.
Thanks to Hans i got it sorted. Was on a C360 with a bent laser glass cleaning rod.
Well no rod on this model but i would also say something is obscuring the laser from reaching the drum.

Only other thing i can think of would be primary transfer voltage not making it to the transfer roller in the ITB.
Bad contact on the machine side or the HV supplied?

Nothing blocking the laser, from what we can see, but we will change the complete PH anyway. We suspected the transfer roller, for black, in the ITB. Replaced the unit and checked for poor connections etc.... As yet, we haven't gone down the HV route.
Thanks.

[AjitN]

Hi
PH unit could be problematic.
Also pls check developer unit for less developer in qty or Trim bar out of adjustment.
By any chance right side door was taken out and fitted back, check the alignment for proper engagement of transfer roll and ITB. Or ITB itself.
This chance is remote as it will affect all the colors. best thing is to try with known good developer unit and drum unit.
Hope this helps

[Gaffers01]

I presume with 25 years experience each they have actually stopped the machine when
the black has written to the transfer belt and drum to have look at what image is actually being processed?

[Guy Milner]

It was the Print Head. First time we have had an issue with a complete PH on the newer kit.