C451 banding & shadows

[pozar]

Our beleaguered C451 started to display two faults with K prints lately, and I'm trying to figure out what's up. (I'm not a tech, but we're a poor non-profit so I end up doing light tech stuff)

The first problem is persistent, and it's a line on K in the print direction:

42226

I'm looking through the service manual and the stripes seem to match the error described below. [p 709]

42225

I've done steps 2-5 as far as I can (haven't measured over the contact terminals, but everything looks fine afaik). There doesn't seem to be an electrostatic charger wire for K, so I skipped that.

Haven't gotten to the PH unit yet as the cleaning jig is missing, but thought I'd check with you folks to see if there's anything else I can try except getting a cleaning jig, before giving up and giving a tech a call.


The second problem is intermittent and doesn't appear over the whole printed page – some parts get a "shadow". Haven't found anything corresponding to the fault in the service manual, and after the above mentioned cleanup of the PC drum a test pattern prints fine at the moment. (But as I wrote this is intermittent)

42227


Any suggestions greatly appreciated.

Cheers
Mateusz

[blazebusiness]

Our beleaguered C451 started to display two faults with K prints lately, and I'm trying to figure out what's up. (I'm not a tech, but we're a poor non-profit so I end up doing light tech stuff)

The first problem is persistent, and it's a line on K in the print direction:

42226

I'm looking through the service manual and the stripes seem to match the error described below. [p 709]

42225

I've done steps 2-5 as far as I can (haven't measured over the contact terminals, but everything looks fine afaik). There doesn't seem to be an electrostatic charger wire for K, so I skipped that.

Haven't gotten to the PH unit yet as the cleaning jig is missing, but thought I'd check with you folks to see if there's anything else I can try except getting a cleaning jig, before giving up and giving a tech a call.


The second problem is intermittent and doesn't appear over the whole printed page – some parts get a "shadow". Haven't found anything corresponding to the fault in the service manual, and after the above mentioned cleanup of the PC drum a test pattern prints fine at the moment. (But as I wrote this is intermittent)

42227


Any suggestions greatly appreciated.

Cheers
Mateusz

Clean the lasers with the Konica provided tool.
Check consumable life and see how far gone the K drum unit is
Run your stabilizer and gradiation adjust

Try that for starters and see if it helps. If cleaning and adjusting doesn't fix it, might be time for a new K drum unit (part# IU610K).

[muhammadreza]

Our beleaguered C451 started to display two faults with K prints lately, and I'm trying to figure out what's up. (I'm not a tech, but we're a poor non-profit so I end up doing light tech stuff)

The first problem is persistent, and it's a line on K in the print direction:

42226

I'm looking through the service manual and the stripes seem to match the error described below. [p 709]

42225

I've done steps 2-5 as far as I can (haven't measured over the contact terminals, but everything looks fine afaik). There doesn't seem to be an electrostatic charger wire for K, so I skipped that.

Haven't gotten to the PH unit yet as the cleaning jig is missing, but thought I'd check with you folks to see if there's anything else I can try except getting a cleaning jig, before giving up and giving a tech a call.


The second problem is intermittent and doesn't appear over the whole printed page – some parts get a "shadow". Haven't found anything corresponding to the fault in the service manual, and after the above mentioned cleanup of the PC drum a test pattern prints fine at the moment. (But as I wrote this is intermittent)

42227


Any suggestions greatly appreciated.

Cheers
Mateusz first you have to clean laser glass if same problem renaming, then you have to clean black developer, and second issue did you see drum and developer life ? i thing your drum and developer need to be change.

[blazebusiness]

first you have to clean laser glass if same problem renaming, then you have to clean black developer, and second issue did you see drum and developer life ? i thing your drum and developer need to be change.

Do not, I repeat, do not disassemble the drum unit to clean the developer since you are not a tech.
Your copies are really not that bad and you will most probably do more harm than good to the drum unit if you attempt to take the unit apart.

Check your drum life under consumables, Run the adjustments I mentioned after cleaning the lasers with the tool provided with the copier. The IU610K black drum unit is cheap ($299) , lasts 300,000 pages, and comes as a fully new unit with drum and developer included. If it is at the end of it's life, replace it. If not, do the cleaning and adjustments.

Also, if you remove the drum unit, Don't forget to make sure the K drum is mounted snugly to avoid developer dumping. Konica made a small metal retaining bracket to keep the black drum unit from unseating.

(or, like many others do, you can put a folded piece of paper between the blue lever and the drum face plate in the absence of that bracket mod.)

[pozar]

Thanks for the advice all, much appreciated.

> Clean the lasers with the Konica provided tool.

The supplied tool is missing, but we improvised one and it seems to have helped a bit. We're going to redo it with another tool (we'll just lasercut one since I can't even find an original to buy)

> Check consumable life and see how far gone the K drum unit is

All consumables are less than halfway through, so barring manufacturing faults they ought to be OK

> Run your stabilizer and gradiation adjust

Done, but not much difference.

> you can put a folded piece of paper between the blue lever and the drum face

Hah, found an old piece of tape there. Will replace it since it fell off when I pulled it out.


Right now, we're going to try cleaning the glass of K with a better tool, but if that doesn't help I'll take your advice and either get a new drum or call in a proper tech.


Cheers
Mateusz

[raplma]

I assume you've checked the transfer belt for scratches?
Regards the laser cleaning tool, this was usually stored in the paper drawers, and is a long grey piece of plastic with a pad on the end, spare pads were also stored in the drawers.
I assume you're not in the UK, as we've just sold our 6th and last c451 and have shed loads of used spares up for grabs.
Mark

[pozar]

I assume you've checked the transfer belt for scratches?
Regards the laser cleaning tool, this was usually stored in the paper drawers, and is a long grey piece of plastic with a pad on the end, spare pads were also stored in the drawers.
I assume you're not in the UK, as we've just sold our 6th and last c451 and have shed loads of used spares up for grabs.
Mark

Haven't checked the transfer belt yet – I'll put that on next weeks todo.

As for the tool, I know where it's supposed to be but it's missing. (That other clamp-like tool is still there though).

Not in UK unfortunately… You don't happen to have a picture of the part? I've only found drawing or pictures of the packaging.

[raplma]

Regards a pic, the spares are all boxed up, but I'll check the one box that i can easily get to and if we're lucky it'll be in there, if so I'll post a pic.

[raplma]

Alas it seems to be the one thing we no longer have, they must have all gone with the last machine.

[pozar]

Alas it seems to be the one thing we no longer have, they must have all gone with the last machine.

I imagine that they're prone to disappearing…

But it's nothing more than a flexible flat piece of plastic with a pad on it as far as I can tell, so we ought to be able to make one ourself on the laser cutter.