KeepItPrinting.com

[tech2tech]

I have a 3000 that prints grey scales very light. When I print the test page with the cylinder the back ground in the graphics box is almost gone.

Here is what I have done::::::
Replaced the Drum, Developer unit(and rebuilt) wire assy and print head.
I have verified all voltages on the board and confirmed all settings in service mode.

I can darken the image by changing the density setting to dark but it still is not where it should be. I also noticed if the scanner is left back so the light hits the drum everything prints good and solid but I do also get the shading from the light.

I have 3 machines here to swap parts between so I will try all suggestions and the first to come up with a solution i will have message me an address to send a gift card.

Good luck and have fun!!!!!

[bigal]

Have you tried the print head density adjustment? You can lighten or darken each segment of the LD head. Also is print head moving freely up and down? I have seen this if its locked or stuck in upper position.

[tech2tech]

Thanks for the reply. I have adjusted the strobe timeing from one extreme to the other with very little change. I also removed the print head shims and put paper inbetween the shims. again this makes it slightly darker and lighter but not where it should be. The head does move freely up and down.

This is a brain buster for me and I wont be able to sleep until I know what is going on. The last thing I can think of is to verify the voltage going to the head, after that I will be at a loss.

[tjohnson]

Are you absolutely sure the drum end blocks are flush against the inside frame of the machine? I had one that took me 2 months to figure out because every time I pulled the drum the flange on the end block would not sit flush when I'd screw it back down.
I have also seen this caused by the drum needing waxed or replaced, but you said you did swap it already. Hopefully it was a known good drum.

[tech2tech]

I did verify the drum end blocks were flush and yes the drum came from a good working machine. After I swapped parts between the 2 printers I ran the good one to see if any of the parts I put into it "would bring the problem with" but I get good prints.

the only thing I did not put in the original post is the customer said the machine has alwayse printed like this since he purchased it new. It currently has 48,000 sq. ft. on it.

Thanks for the post.

[mark in vegas]

If the problem has been there since new it still sounds like printhead position. The other ares I'd take a close look at is the printhead lens/glass. It doesn't take much contamination to cause what you're seeing.
_________________
Regards,
Mark
RVN 68-69
It's so nice to be insane
No one asks you to explain

[tech2tech]

Thanks Mark. I have swapped the head between 2 machines. both heads work great in one and both are light in the other.

[mark in vegas]

Have you tried swapping the drum hubs? (machine side)
_________________
Regards,
Mark
RVN 68-69
It's so nice to be insane
No one asks you to explain

[tech2tech]

I will do that. I was planning on pulling them off to check the underside after Tjohnsons post but I will just swap them.

[bigal]

Check Transfer voltage and charge voltage as well. I assume wires are clean and correct height?

[dlee]

Confirm that the drum blocks are flush, AND make sure that both screws are at the end of the slide slot. I've seen where one screw was flush to the end of the slider and the other was not. It would seem impossible if you are just rotating the blocks but the sliders are wide enough that you can physically move the block side to side (not circular) which would make the drum uneven. Then I would push the LED Printhead up and lock it in the shipping position. Close everything up and instead of just loosening the lock brackets to drop the LED Printhead, remove the brackets right out of there. Don't worry, printhead won't hit drum due to the two pins at each end that sits on the drum blocks. (I remember, many years ago, KIP actually recommended removing the brackets.) Try this and let us know how it goes.

[tech2tech]

Ok here is where I am at. I pulled the side brackets off the print head lid to be sure the head was going all the way down. I replaced the drum blocks. Verified the voltage on the print head, replaced the controller PCB, cleaned the drum ground and disconnected the drum cleaning lamp. Did not notice any change. I increased strobe timeing #9 from 10 to 13. The prints got darker. But on the display panel if I make a test print changing the density settings from light to Dark there is no noticable change. The problem I am having is just with the grey scales. Blacks print solid.

I am about ready to make this a parts machine but my curiosity is getting the best of me just to figure this out. I have replaced every part in this that I can think of and it does not effect it.

Any more thoughts...........?

[tech2tech]

Bigal I verified all voltages, replaced all wires and set the heights when I first started.

[mark in vegas]

Since you have a parts machine or two try swapping the IPS. Have you compared the density settings in Printnet? On the Acroplot site they have a test pattern that contains a bunch of line weight examples and gray scales. Might help narrow this down.
_________________
Regards,
Mark
RVN 68-69
It's so nice to be insane
No one asks you to explain

[tjohnson]

The last thing I can think of is developer unit position. Are the cams or camshaft bent or out of position? There are metal spacers you can remove or add to keep the forward position to the drum even. Any chance the DV unit is not at close to the drum on the one side as the other side?