470W with background

[totoro]

Hey Guys,

I have a 470w that has had developer and charge unit changed in the last 6 weeks. It now has a fairly heavy background on the copies. I don't have very much experience on these machines and wondered what to do about it. On a smaller machine I would probably run a few sky shots to detone and run td initialise. How do you detone a wide format? Any advice appreciated. TIA

[gregoriojc]

check monthly average volume according to that swich to los or high volume,
also check the and clean the charge corona unit you will see a white dust stick to corona wire and the corona metal case, it wiil improved copy quality ,we have the same problem here but totally you can not removed the background .

[banginbishop]

I have a 470 that does a speckly background - looks like a classic overtone. First thing i done was change the dev but the problem was still there so i changed the drum and the copies are fine. Have had the same problem again and i just replaced the drum again to cure the background issue - i did think it was a bit soon for the drum but after checking the counts it was due for change.

If you suspect the dev, check the vsg etc. Check the connector on the dev unit is connected as i have found that sometimes people forget to connect it when the dev/drum unirts are removed. Make sure the mylars have not cracked and broken causing toner to sit on the sensor under the dev unit.

These machines are old and the dev units are showing this.

[vitorjorge]

In wide formats with dirty background the solution is to change the drum.
Changing the charge corona will only minimize the problem.

VJ

[totoro]

I went to the machine this morning and cleaned the id sensor and the charge unit and set it for high volume. I'll change the drum if the problem reoccurs. Thanx to all for suggestions.

[NCArt]

I had several machine with this problem. The best fix I found was to reduce the DV bias to -500v +/- 50. This has worked on 470, 480, and 240.

[pspahr]

Check and replace the ozone filter. The machine doesn't read the td sensor like traditional Ricohs. If you have a service manual read up on the development section.

Back to ozone filter: airflow is critical. Also, check to make sure drum grounds good. Speaking of drum, whats the count on that?

NCArts probably right, also, give his fixes a try, also, may save you on an old drum.

[Shadow1]

Most machines when the drum starts to go you can see some sort of damage - color change, grooves, etc - these just die. If you have backgrounding do the PM and put in a drum. Changing the corona cleaners is also critical on these - the wires get dirty fast enough as it is...