IR 9070 Intermittent fading on T.E.

[totoro]

Hi All,

I've got an IR 9070 that the printing on the trail edge fades intermitently. Usually 2 out of 10 or 15 will fade. The only way I've been able to fix this is by replacing the pre-transfer corona ass. This only lasts about 500k though. The machine only has 2 mil on it. Other than this it runs fine. The other 2 machines I have don't have this problem. Is there something that I'm missing here? Has anyone run into this and found a fix? TIA

[Guest]

Hi All,

I've got an IR 9070 that the printing on the trail edge fades intermittently. Usually 2 out of 10 or 15 will fade. The only way I've been able to fix this is by replacing the pre-transfer corona ass. This only lasts about 500k though. The machine only has 2 mil on it. Other than this it runs fine. The other 2 machines I have don't have this problem. Is there something that I'm missing here? Has anyone run into this and found a fix? TIA

What made you decide to change the pre transfer, the pre transfer attracts stray toner, thats why it when you pull it out it has toner. Why don't you replace the primary corona assy. Sounds like you have a charging problem.

[totoro]

I had this problem before and went to change all the corona units one at a time and the pre-transfer was the one that fixed this issue. I've had it happen on an IR 105 and IR 8070 as well and the pre-transfer fixed the issue there also. The 9070 is the only one that repeats the problem every 500k or so. I do change the wires at around 200k.

[Oze]

Do you replace the scraper as well?
I'm with Screwy....whenever I've had image fading on one side I either adjust the height of the primary wires or replace with a refurb or new unit.
You can run the machines with the pre trans out so I'm puzzled as well as to why it's making a difference in your case.
Rule of thumb tends to be faded down one side=primary charging....
faded all over tends to be trans-sep coro.
Have you checked the toner coverage on the dev cylinder?

[totoro]

Yes, I have checked the toner coverage on the dev cylinder. It's fine. I'm starting to think that I'm having a problem with the HPS or process control;though I've turned off P.C. with no visible change. It puzzles me.

[20YRSEXP]

Technically the corona assemblies are rated for 500K, but you can usually get double the life. The Pre-transfer doesn't just remove toner with the incorrect polarity it also helps loosen the drums attraction of the paper. If the Pre-transfer isn't working well it can cause the trail edge to hold and it will cause fading when it drops off the drum and leaves some toner behind. You can try adjusting the charges in service mode that will sometimes help. There is also an adjustment for the trail edge fading in copier>option>body>trsw_p_b. it is either 1 or 2, try changing it.

[totoro]

I should have the corona unit this week. I'll try your adjustment. Thanx !!!

[c1sc0m4n]

Been a few years but I thought I remember replacing the t/s assy, as the paper may jump up at the very end. The 8500's were notorious for this.
I have always taken the pre trans wire out---causes nothing but trouble...

[jtecks]

Have to agree with c1 as my experience has been poor separation especially 7200/8500/105.

[Canuck]

Make sure the varistor for the transfer guide is not open and connected. You said problem is on trail edge...primary wire height affects front to rear. I have had to reform the transfer guide to fix this problem also. Lots of service mode settings to tweak also

[totoro]

I went back to the machine this morning and swapped out the pre-transfer corona unit and the fading stopped. I checked the setting at copier>option>body>trsw_p_b and it was already set at 1. T varistor at the transfer guide is fine and I did not see any deforming of the transfer guide. Which service mode settings do you tweak, Canuck?