Ir600 faint copy-print problem ghost

[kingpd@businessprints.net]

Hey guys,

I have a problem on an imagerunner 600 that's been bugging me. When a print run is started on this machine (duplexed) page 1 of 2 (page one is face down on the stacker) will print every 3 or so out of 5 copies with a faint printing about 2-3 inches from the left side and on in. It's fairly consistent. A longer document will do the same thing.

I have tried with no success the following:

1. Replaced the corona wires above and below the drum;
2. Ran several clean corona wire attempts in service mode;
3. Tried many brands and weights of papers with no success;

Now here's the mysterious kicker. After about 50 to 100 sheets are run through the machine with this faint printing problem...the problem goes away. It will print tens of thousands of sheets with out any further problem. It's almost like something has to warm up for the problem to go away.

The only thing I can think of right now is maybe adjust the develop voltage, but why does the machine correct the problem eventually?

Any help would be greatly appreciated.

Thanks.

[teckat]

Hey guys,

I have a problem on an imagerunner 600 that's been bugging me. When a print run is started on this machine (duplexed) page 1 of 2 (page one is face down on the stacker) will print every 3 or so out of 5 copies with a faint printing about 2-3 inches from the left side and on in. It's fairly consistent. A longer document will do the same thing.

I have tried with no success the following:

1. Replaced the corona wires above and below the drum;
2. Ran several clean corona wire attempts in service mode;
3. Tried many brands and weights of papers with no success;

Now here's the mysterious kicker. After about 50 to 100 sheets are run through the machine with this faint printing problem...the problem goes away. It will print tens of thousands of sheets with out any further problem. It's almost like something has to warm up for the problem to go away.

The only thing I can think of right now is maybe adjust the develop voltage, but why does the machine correct the problem eventually?

Any help would be greatly appreciated.

Thanks.

How old is Dev unit ??

in high humidity conditions there is less toner used per rotation of the developer sleeve.
This can cause the toner to stay in the developer for extended periods of time,
consequently preventing toner particles from remaining fully charged. This results in less toner being carried by the developer roller sleeve and therefore light images.
(there was an adjustment procedure years ago for the magnetic pos plate) but u probably have changed this unit after that.

since your issue disappears after a long run , I would lean toward machine environment.

check under >Display > ANALOG > that both TEMP and HUM are ok/ if not

Sensor Unit- Humidity ( FH7-7342-000 )and or Cable Harness ( FG6-1901-000 )

[kingpd@businessprints.net]

How old is Dev unit ??

in high humidity conditions there is less toner used per rotation of the developer sleeve.
This can cause the toner to stay in the developer for extended periods of time,
consequently preventing toner particles from remaining fully charged. This results in less toner being carried by the developer roller sleeve and therefore light images.
(there was an adjustment procedure years ago for the magnetic pos plate) but u probably have changed this unit after that.

since your issue disappears after a long run , I would lean toward machine environment.

check under >Display > ANALOG > that both TEMP and HUM are ok/ if not

Sensor Unit- Humidity ( FH7-7342-000 )and or Cable Harness ( FG6-1901-000 )

Thanks Teckat,

I actually acquired the machine from one of Canon's direct sales offices about 2-3 years ago; the service records are sketchy and there's no notation on a developer unit being changed or any related procedure being done. I'm more of a generic tech with official training on Konica Minolta machines so I don't have the service book and so far haven't needed it nor am I familiar with the adjustment procedure. I get parts from a guy I know that works for a Canon dealer but unfortunately there's not really anyone at their firm that works on these older ones. I think I may actually be more familiar with this series than they are.

Here's the information from the readout:

Temp 23C
Humidity 20% (I think anything under 45% for winter is ok?)
Optics 71C
Fix-C 199C
Fix-E 175C

I'm guessing these are ok?

Thanks for your help.

[teckat]

looks like u should replace dev. unit

FG9-3906-000 just-DEV UNIT

FG6-2010-000 DEV UNIT & HOPPER UNIT INCLUDED

[SCREWTAPE]

What's the count on this unit. Laser units can also cause intermitted light copies. Check D-Pot values in service mode VL1M should be around 72-75v. VL1T should be about the same. If VL1M is 300 or higher then your laser unit is going bad. Pre-exposure can cause issue like this as well. Did you try turning off potential control?

[abemiami]

Faint copies on IR-500-600 series...

I had that issue before, turns out the problem was caused by the toner stirring roller inside hopper unit, not an easy to find problem, but that was the cause and it has happened to me in more than one of these already....hope it helps...but let me know iether way....