Konica Minolta Bizhub C550i abnormal image

[Mr. Breaker]

Hi,

This week we had an interesting case with a Konica Minolta Bizhub C550i (machine with memoryboard)...

The customer compliant about color copies, as there was an dotted pattern as background to the image.
When outputting the “testpage” (the one with the bird), only K is doing the correct gradation pattern but all colors (so C,M & Y) don’t do any gradation. So any RGB gradation pattern is 100%, so the 5% gradation check area has an solid 100% coverage and the photo of the bird is (almost) solid black.

Machine was on firmware version AA7N0Y0-F000-G00-K8-970.

We changed the baseboard, but the problem was persistent.
To make a long story short… It turned out to be an simple fix. Just alter the “function version” (softswitch 25) of the machine and change it to any existing function version and after the alteration, change it (back) to the appropriate version (in our case hex 30, so v2.2) and the problem is solved. This problem can probably also happen on the C450i and 650i (or maybe even C250i, C300i or C360i, not sure though about this slower series…)

As you can imagine it was quite “an ride” to find the solution… So I post it here so you guys won’t have to invent the wheel and make a lot of expenses on parts and boards that aren’t the solution. For reverence I added the abnormal “testpage” output of the machine.

52500

Best regards,

Mr. Breaker

[blackcat4866]

Congratulations on your success! =^..^=

[tsbservice]

First of all, thumbs up for you posting this thread, not many come here with solutions not questions!
Secondly, would you mind sharing some more info like:
- exactly how problem develops(assuming it's not on new installation)
- counters
- how on earth you come to an idea downgrading function version and setting it back appropriate
- some more samples like counter page, CMYK halftones, etc.

[Mr. Breaker]

First of all, thumbs up for you posting this thread, not many comes here with solutions not questions!
Secondly, would you mind sharing some more info like:
- exactly how problem develops(assuming it's not on new installation)
- counters
- how on earth you come to an idea downgrading function version and setting it back appropriate
- some more samples like counter page, CMYK halftones, etc.

- It was an new machine (1,5 week onsite at the customer).
So counters were near 0.
- My hypothesis is (since IT of the customer didn't changed to the new driver yet), that the machine got in this state by the wrong (really old BH C360 driver, so no I series), but I can't tell for sure.
- As stated... all halftone output is 100% coverage. Only K will respond to halftone output.
- First tried, firmware rewriting, second Initialization, swapped baseboard still no joy, so tried several other options, as it turned out to be the function version (as strange as it may sound). But I'm very happy that changing the function version solved the problem, because this could easily become an real nightmare to overcome.

[tsbservice]

OK just to be on safe side was machine at proper functional version prior problem - sw. 25 at hex 30?
I certainly apologize asking too much questions 😊

[Mr. Breaker]

OK just to be on safe side was machine at proper functional version prior problem - sw. 25 at hex 30?
I certainly apologize asking too much questions 😊

No props, that's correct.

Machine was on sw25 hex 30 prior to the problem (and with the problem). Changing sw25 to hex 10 solved the problem. After this... set sw 25 to hex 30 problem stays fixed.

[Synthohol]

does not sound crazy, i just has a 750i blow the cpu board. replaced board and loaded latest FW and changed the bit to 30.
papercut would not work at all. on a whim (and looking at a sister machine that works with papercut) i saw it was at 10 so i changed it back to 10 and all was right in the world.

[tsbservice]

does not sound crazy, i just has a 750i blow the cpu board. replaced board and loaded latest FW and changed the bit to 30.
papercut would not work at all. on a whim (and looking at a sister machine that works with papercut) i saw it was at 10 so i changed it back to 10 and all was right in the world.

That would affect another application I agree but print quality is pretty big imho.

[Mr. Breaker]

That would affect another application I agree but print quality is pretty big imho.

Second that, totally didn't expect to solve the print quality problem with changing the function version.

And to be honest I wouldn't believe it if I hadn't seen it with my own eyes. <= That's the reason of this thread, because one can spend a lot of time and money wasted, while the fix is so simple (and unbelievable)...