Konica r1 - problem colour

[Danielcastrro]

Hello see this images. On right image from printer setup and left print from laptop windows! And Now? I think that was version incompatible!

 

[Minilab service]

Many Konica have it. Printing heads are old and light is weaker. Red should be the most powerful, because paper has the least sensitivity to this color. As result you have not enough Cyan on black area. To compensate it you have to use paper with the biggest sensitivity to Red. Use paper for analog minilabs. Also can correct processor temperatures. Make paper channel balance and manual data adjustment ( especially on dark area ) .

[JerryBenko]

Having similar issues on an R1 where the blacks are not really black but always have a consistent and uniform colored tint to them on anything being printed.

It seems that this is due to the light source in the exposure head being a bit "tired". Now the Service Manual isn't very clear if the light source used for exposing the paper is fluorescent or LED. It seems from the block diagram that RED is LED while GREEN and BLUE are vacuum fluorescent tubes..?

Also, since the blacks are only slightly off but beyond chemical / software correction, is there a way to adjust how hard the light sources are driven in the exposure head?
Like a VR (potentiometer) somewhere on a circuit board? 

Many thanks in advance & best regards.

Edited March 16, 2021 by JerryBenko

[aptucta]

This is how the led board looks like, it is located under the small fan in the exposure unit.q very easy to remove... it is just leds, if you find the right leds probably you can rebuild it yourself. 

Edited March 16, 2021 by aptucta

[Minilab service]

Which processor do you have - standard replenishment, or ecojet? If standard - which chemicals do you use? On Konica should be used only fast process chemicals. 

Do you have black, if process fogged paper? From magazine remove end of paper and leave it in the light. Then return paper to magazine and print something. Processed paper should be totally black ( because it got light ) . Only if have good black you can search something in print engine. If black is bluish then need to check developer, check replenishment rates, calibrate replenishment pumps,  check temperatures and calibrate temperature sensors. 

2860H1320A is LED unit from R2 series minilabs. R1 light source has absolutely different design. There R is LED and G. B - fluorescent.

Edited March 16, 2021 by Minilab service

[JerryBenko]

Thanks a mill Aptucta for the reply and photo!

The actual board is yet to be checked for any faulty or dimmed LEDs, but I was wondering if the drive current can be adjusted somewhere for these OR for the fluorescent light source? BTW the prints show a green cast ONLY in fully black areas, the rest is OK.

This would suggest to me that green light source is weak, not reaching its required peak brightness. Now since that's essentially a CCFL tube I either replace the tube or drive it a bit harder - the latter being easier of course.

Dear Minilab service, thanks for your reply too, appreciate it! I'd need to check in the lab which type the processor is (it's quite a new acquaintance) but it was filled with the matching chemical that I'm sure of. Also, exposed paper check was done and then there's perfect black so the chems are OK.
And yes, you're right this is an R1 and the block diagram shows the Red LED and Green/Blue fluorescent.
As I wrote above my diagnosis is that the Green light source is weak not reaching peak brightness required for correct blacks but good enough to get fairly good color rendering otherwise. Same question on my mind: can the driving current be adjusted for it..? Or the tube be replaced? I know I can replace the whole unit but if there was a chance to save it why not.

On the long run I'd love to get rid of the CCFL for Green and Blue but I have the feeling it's not possible to just modify it for LED... That'd be buying an R2 instead.

 

[Minilab service]

Which color is too weak on the paper? Red color light source on paper gives Cyan. Red light source is LED. Green light source on paper gives Magenta and Blue light source on paper gives Yellow. Green and Blue light source are fluorescent lamps. Blue light is the weakest, Green - in the middle and Red - the most powerful. Usually Red color power is not enough and have not good balance.

Black balance depends on print engine and chemicals. You didn't provide any information about processor, so can't say anything.

As I told before on picture uploaded above is R2 light source. There used only LED.

[JerryBenko]

I've confirmed that the Konica Minolta R1 printer is configured and operated with Tetenal Ecojet chemicals (tablets).

Let me re-iterate again, maybe I didn't phrase it well enough
1. The paper has a slight green cast but only in the totally black areas. So anything which isn't absolutely black has a fairly good color rendering.
2. Pre-exposed (fogged) paper comes out pitch black plus the chemicals were tested outside the printer and worked flawlessly.
3. My logic was that if pitch black has a green tint then the green light source is weak, not able to provide the required peak brightness for exposing total black.

Question: Is my logic right, or did I get it wrong? If pitch-blacks have a green cast which light source causes it in your opinion?

Many thanks!

[FUJI-MEDIA]

You irradiate negative paper. If you have a "green" shade in the shadows, then you are out of power in the red light source. ("green" is probably in reality cyan).

This would mean the problem is with the red LEDs or their driver.

[Minilab service]

FUJI-MEDIA,  sorry, but you are wrong.
If dark area has Cyan color then Red light source would be too powerful. Red light on paper gives Cyan color. Typical R1 fault is too weak Red light source ( LED ) . Then printed pictures are RED - Magenta. Look at picture uploaded above ( Danielcastrro uploaded it ) .

If dark area is Green then Green light source is too weak. On paper Magenta density is too low.

Too low Magenta ( on paper ) is not typical fault. To see what is missing the best would be to print black and measure with any external densitometer ( some Xrite ) . 

If some color level is too low can try to set a little higher developer temperature. All colors will be more active. Which paper do you use? Black level is limited and depends on paper, which you use. If after temperature increase missing color reach paper maximal level you need just calibrate printing profile and can continue to print.  

 

 

[FUJI-MEDIA]

Minilab service 

YES YOU are right! 

There is too much red light, or too little blue and green.
As always, you are right!

[Minilab service]

Too much light can't be. Each paper has density limits. They depends on paper maker, brand and type. The best see what is missing can see if to print black and measure.

On Konica minilabs used fast process. Not all papers can be used there. JerryBenko didn't tell, which paper he use there. Maybe this paper can't be used on this optical exposition minilab. Some papers can be used only on laser minilabs.

If slightly increase tank temperature then chemicals are more active. I did it on Noritsu minilabs, when converted them from SM to standard. 

[JerryBenko]

Thanks guys, appreciate your replies! Then it is indeed the Green light which may by weak...

The paper we use is Fujicolor Crystal Archive. As for raising the processing temperature that's been tried but did not help the issue...
I'm going to check if a printing profile recalibration was done after raising the temperature.

Out of curiosity, is there a potentiometer somewhere which would adjust the Green light intensity (like driver current or similar)?
Or is it possible that dust settled somewhere inside the exposure unit and a simple cleaning would fix it..?

Of course I would be happy if it could be fixed just by some setup / configuration without touching the hardware.

[FUJI-MEDIA]

I examined the printouts one more time. In my opinion, not only is the right print greener in its shade, but it also has a significantly lower density as a whole. Not only in blacks. If both prints were made with the same density correction, then I have already encountered such a problem. The problem was caused by too slow replacement of the developer through regeneration due to insufficient processing volume of prints recently.

Maybe replacing the developer with fresh one will help?

[JerryBenko]

So here's what's been tried so far:

Replace all chems with fresh new

Replace paper with fresh new (same Fuji CrystalArchive)

(Paper and chems work flawlessly outside the printer with manual processing.)

Raise process temperature

Create printing profile / run calibration

The same problem remains: colors are OK except pitch black which has a slight green cast to it.

So I wonder: can this be fixed by cleaning off some dust in the right place where dust can weaken the green light?

Or can the green light intensity be electronically adjusted?

Edited March 18, 2021 by JerryBenko

[Minilab service]

Picture above is uploaded by other forum member ( Danielcastrro ) . All clear there - Red light source is too weak. It is typical fault on R1 series printers.

JerryBenko didn't upload picture, so we can just read, what he wrote here. He told, that black color on prints is green. Then Green light source is too weak. Didn't see this problem on R1, but it is possible, that his minilab has this problem. 

Maximal density on Fujicolor Crystal Archive Paper is about 1.9 - 2.0 . So there black color is not so deep as it is on professional range papers ( there about 2.5 ) .

Yes, R1 on Fuji  Crystal Archive should print. If even on quite low density you have Green color then light source is really weak. 

Might be that it is some problem with board. Check fluorescent print head power supply board ( AC018AA, part number 271076903  ) . Test G with other board. Check power suppliers ( +5V and +24V ) on these boards. Maybe some is too low. G is more powerful, than B. Might be power is enough for B, but not enough for G. Also can be not correctly working head-trm board  part number 2710H1220 .

Do not think, that cleaning will help. Probably need change print head unit. If do not want to change you can find some densitometer, print black and measure C, M, Y density there. If you see, that have acceptable Magenta level ( 1.6 and more ) then correcting profile on black can slightly decrease C and Y.  Then you have not very deep black, but your black will not be green.

[JerryBenko]

Thank you Minilab service, I'm indeed grateful for your advices!

I'll ask for one of the failed prints which shows the greenish black issue and upload it here - you're right it's better to see it.
I'll also take a look at the voltages of the  AC018AA board for starters...

Out of curiosity, what professional brand/type of paper would you recommend instead of the CrystalArchive?

[JerryBenko]

Good afternoon guys,

So I got a sample print which I scanned showing the issue. Also made a Photoshop corrected version next to it for easier comparison.

 

[Minilab service]

For me it is similar to bad chemicals, or too low temperatures. The most missing Magenta, but other colors are bad also. Please print test photo, where can see all colors separately ( Konica test for minilab calibration with scanner, Fuji test with girls, and similar ) . Also run control strip and look what you see there. Measure control strip with colorimeter. Check tank temperatures ( with electronic thermometer ) and calibrate Konica temperature sensors.

[JerryBenko]

Thanks Minilab service! That's a fair amount of homework to do  and sounds all logical. I'll do the checks and calibartion, test prints may have to wait a bit as currently the printer needs new, fresh chems but of course will do that too.

[Tomtom]

It looks like the developer is contaminated or missing 1 part of developer. Does you developer is monopart or 3 parts like A, B, and C? Check the part B maybe oxidised. 

[Minilab service]

Here is ecojet replenishment - using tablets ( Ecojet-P ) made by Tetenal. Working tanks need to fill prepared chemicals. Latter replenishment using tablets and water. On Konica used fast process, so processing time very short. 

I agree, that developer is bad. All colors are not normal, missing contrast, so here is some problem with chemicals.

Tomas, I wrote you private message. Please read it.

[oto]

Здравствуйте, можете ли вы мне помочь? Мне нужен образ Windows 2000 Professional для моей Konica Minolta R1! Возможно, вы сможете мне помочь.

 

Edited September 19, 2025 by oto