MPW 2401 shadow around text and solids

[davel]

Guys,
I am a total newbie to these wide formats, have inherited this from another dealer have no history of machine meter is 6000 metres A0 size only. Shadow around print mainly nearer to the outside areas. I have replaced the dev x 2 but no difference, any suggestions.
Ignore the small spots, the scanner I used had a dirty glass.

[keithxxiii]

Re: MPW 2401 shadow around text and solids

I thought it was an optical illusion...

Anyway, have you checked the health of the drum and drum case assembly? It could be that the cleaning blade is quite deformed from both sides.

[JDYAL]

Re: MPW 2401 shadow around text and solids

Like Keith said possibly drum and cleaning unit. Also check the developer bias it should be around 600. Don't rule out a old main charge corona either.

[Brianneoe]

Re: MPW 2401 shadow around text and solids

Toner on the LED array can give you this problem..

A quick way to clean the LED array is to remove the original feed tray (2 screws). Remove the 2 screws holding the DF unit in place and the drive belt for the DF rollers.The screws holding down the DF are towards the rear in the same area of the DF drive belt. Now the DF will pivot up and you will see the main charge and drum. On both sides of the LED array is a latch that is keeping the assembly in place. Loosen up the two screws and pivot up the LED array. The LED assembly is 3 separate units that you can now clean with a soft cloth. Don't use any chemicals on it.

Keep in mind that the DF unit when in the up position can free fall back down.

Good luck

[davel]

Re: MPW 2401 shadow around text and solids

Excuse my lack of experience with these machines but would not dirty LED give white/pale lines same as a dirty laser glass?

[Brianneoe]

Re: MPW 2401 shadow around text and solids

Hi Dave, you are correct about what we would think a dirty LED array would produce but its been my experience that this is not the case with these machines. I should have added more information from my reply. I have seen this Halo effect before and would do two things. Cleaning the array unit and changing the grid\charge wires. Most of the times what I would find is toner on the array unit and the charge grid in the same area. Its quick and easy to get to both by flipping up the DF unit. Just keep in mind if you are going to remove the charge unit by this procedure you will want to keep the LED unit up and be very careful when pulling out the charge block. There is not a lot of room on the left side to get a good grip on the charge unit and if it slips you can scratch the drum. Un-clip the wire harness on the right side and move the cables out of the way as to bring out the right side of the block to a point where the left side is clear. No need to remove the charge block holder on the left side unless the unit is sticking to it and won't slide out freely. Keep the leaf springs screwed down before you remove the the charge connectors on the right side,the inside connector is a pain to remove and you will need your needle nose pliers.
Once the left side is clear you can now bring the block out from the top.

The safest way to bring out the charge block is to remove the drum unit but that adds about a hour more to the repair.

About every 2 years the main charge\grid wires will need to be changed on theses machines. You will start to see "Toner Worms" when the wires get old and the humidity levels go down. I don't know how many of these unit you have out in the field but I keep in stock about 10 charge units in my parts inventory and then restring the unit when I bring them back. A lot easier doing to in the shop then in the customers office.

If you find a lot of toner dusting on the right side (charge block connector side) you may have a sliver of paper stuck in the drum cleaning coil causing it to dust up. Do yourself a favor and remove the drum and check if this is the case. A clogged coil will compress and chip the drum.

Good luck