Konica Minolta 1051 Density inconsistency

[cmitchprint]

We installed a KM 1051 digital printer that boasted exceptional print quality and up to 1200 DPI printing. The problem is, there's nothing exceptional about the quality and half-tones print inconsistently throughout the job. Our service tech doesn't know how to fix the issue. You can print 100 sheets of the same picture and the black density bounces around throughout the job, printing some clearly while plugging others. Furthermore, the density is darker on one side than the other. This issue has become quite frustrating and I was wondering if any techs have had this issue with this machine and knows how to fix it.

 

[Emtri]

What sort of stock are you running on?

 

[graymatter]

Transfer roller? KM knowledge base has a mention of excess plastic on the drum carriage shoulder screw, too. Mention it. We've not seen this issue, but then my techs tend to be clean freaks. That's a fine box and shouldn't disappoint. I'm overseeing the install of one on Friday

 

[cmitchprint]

The stock doesn't matter since it does this on all stocks.

I'll mention the drum carriage screw to service this a.m. But, they cannot seem to be able to fix this density fluctuation. We have a 12 x 18 #24 sheet that has the same halftone 4 up and all 4 are fluctuating in density. We also have noted the density is darker on the drive side of the machine and quite a bit lighter on the operator side. They took it apart and cleaned the toner out. It has a HUGE dusting problem and they don't know why. It'll dust toner everywhere. They have installed a new drum charge corona, new charge belt, new rollers. The ONLY thing that hasn't been replaced is the drum (it was replaced by the previous dealer which makes me think they had an issue). This is a 'demo' model that had about 250,000 copies on it when we got it. Present meter count is about 689,000. It was installed in April.

After they put it back together at 5:00 p.m. yesterday, we could not even get a sellable sheet off of it. This machine disappoints me tremendously. It has had the issue since day 1. 1200 DPI? NOOO way! It won't even print clearly the 'Bible sample' they so proudly showed off at the show. And what sold us on this machine was the 1200 box that was shown at the show in Chicago last year.

Service informed me they have contacted KM tech support on this issue. We have a great service crew and I've never seen a problem they couldn't fix but this is a stumper.

We just ran the picture section of this book on our C6500 in grayscale and the quality is SUPERB! Too bad the 1051 can't match it.

 

[Craig]

It must be something they have worked out when they introduced the 1200. We just had one installed in July and it is awesome! We have not had any problems that you have suggested, the only trouble we have had is a broken part on the saddle stitcher. A little Gorilla Glue and we were back up and running till the new part arrived.

 

[cmitchprint]

Update: Corona Scoretron was on upside down. No change in quality. The service is installing another drum as I write. Not much hope that it can be solved with this replacement. The fear we have now is that we found out the original purchaser sent the machine back (we didn't know this when it was purchased) because of unacceptable quality. Our service has discovered 'trouble tickets' galore but they have no access to these tickets. Only Minolta techs can access them. GREAT! We're trying to figure out WHAT we are going to do since the machine is no longer under warranty and even though it's under service, sending it back isn't an option. It looks like we've been 'duped' with a lemon machine.

BTW, manufacture date is January, 2010.

 

[Emtri]

Was the 6500 you ran said sample on in your shop as well? Its possible there is a RIP issue.
Although if its dusting toner like that I highly doubt it

It sounds to me like theres a problem with the drum unit or possibly the cleaning blade on the drum. If the toner is clumping up alot along the cleaning blade there, its possible theres some sort of issue with the toner waste/reclame assemblies .

Also under warranty or not, if you have a service contract and they are unable to resolve the problem. You should be able to get a replacement machine out of the konica. If you want to go that rout speak with your post sales rep or the Service Manager and push for that. If your in canada, I know the person you should contact. (assuming you're dealing with konica directly and not through a re-seller, although you may be able to do that too, but I have no experience with resellers)

 

[kalindd]

Advise your tech to try this, if he hasn't done it already.

Description
How to adjust for light density/poor fill in a high altitude, low humidity environment.
Solution
In altitudes above 6000 feet with relative humidity below 25% it may be necessary to compensate for charge potential and transfer issues by performing the
following adjustments:
1. Reduce thedeveloper bias voltage by 33% (Example: if set to 90, reduce it to 60),due to less charge on the drum at this altitude.
2. Increase the amount of transfer by 33% (Example: if set at 27, increaseto 40).
Notes :
a. Be careful not to set transfer too high or corona arcing may result.
b. It is very important to perform the procedure to improve solid density on single or duplex copies at the same time that these adjustments are made.

 

[graymatter]

If this machine has a history and can't be made right, *I* would pitch a fit. Perhaps the drum carriage is warped. That's an LED printhead, not laser. Drum-to-LED gap uniformity is critical. Have they swapped the printhead? Maybe this machine had a particularly rough delivery or was manhandled by an install tech? You can't know these things for sure. But the machine in general is tight. If this particular one is flaky, your dealer/branch should resolve. Who are you with? A dealer or a KMBS branch office?

 

[cmitchprint]

Update

Update

Service replaced EVERYTHING except THE DRUM and no dice. So, everyone is staring at the drum and I see these lines all over it and coating appeared to be missing in places. Service techs had brought a drum with them preparing to replace it. Well, the drum gets replaced and no more density inconsistencies from side to side. Crisp and clean. We suspect that the previous dealer that had the machine put an aftermarket drum in it. It was not even the same color. Furthermore, the service meter had shown a new replace when the machine was sent to us. I seriously doubt that it was replaced as they said. The old drum looked like it was rode hard and put up wet.

Drums are supposed to last 2 million so they say. I highly doubt we'll ever see one last that long since we barely get half what they say we can out of the C6500 drums. So, far, all is good and we'll wait and see if we can maintain the quality. I hope they solved the toner dusting issue as well. We'll see.

 

[Emtri]

The 1050 Drums are designed to last longer then the 6500 drums as they are just black units rather then KMYK

 

[graymatter]

Service replaced EVERYTHING except THE DRUM and no dice. So, everyone is staring at the drum and I see these lines all over it and coating appeared to be missing in places. Service techs had brought a drum with them preparing to replace it. Well, the drum gets replaced and no more density inconsistencies from side to side. Crisp and clean. We suspect that the previous dealer that had the machine put an aftermarket drum in it. It was not even the same color. Furthermore, the service meter had shown a new replace when the machine was sent to us. I seriously doubt that it was replaced as they said. The old drum looked like it was rode hard and put up wet.

Drums are supposed to last 2 million so they say. I highly doubt we'll ever see one last that long since we barely get half what they say we can out of the C6500 drums. So, far, all is good and we'll wait and see if we can maintain the quality. I hope they solved the toner dusting issue as well. We'll see.

hurr-de-durr. All that and it was the DRUM? A >CONSUMABLE<? Sounds like cheapitis. Service manager trying to cut corners? Resetting life counters? Chipping imaging units? Skip the service manager and go to the branch mgr/GM/dealer principal. There's no excuse for all that over a drum.

Glad you're fixed, though.....