Sunday Afternoon Sanity Check

[orestesp]

Hi everyone,

Just a quick sanity check. The backstory is this: on my MP6000 I had to replace the developer early (at ~200k, 150k before yield) because the density was too low. I was also getting some shadow SC-3xx logged to the machine in that time period, unfortunately cant remember which specific ones. I'm beginning to see a deterioration in the max density the machine can produce yet again, I should also mention that every other part is original and within yield. What I mean by deterioration is that in the checker flag test pattern, I don't seem to be getting as deep a black as I can get on a MP4001 I have for office use (whose developer is past yield and I use some compatible parts since it's not a priority printer in the shop)! Of course when I had just installed the developer on the machine it was printing a very nice deep black but now after a couple tens of thousands of prints it's not as deep...

I've always followed the bulletin's instructions about thoroughly cleaning everything up and cleaning the grooves of the mag roller with a wire brush but that didn't stop it from happening before. I've also noticed that I may have attached the side seals the wrong way? I've seen some photos where the lower part of the seal seems to be tucked in inside the cavity between the mag roller and the lower metal part of the dv unit but how would that work since I assume you'd have to stick it on the mag roller which rotates? Really not sure what's the correct way since when I got the machine all the seals had deteriorated so badly and thus didn't have a reference when I was replacing them.

Here's some also related info on the issue I pulled from SP mode:

Vl=99
Vsp=0.41 V
Vsg=4.54 V
Auto Process Control is Enabled
Oh and there's also a SC-315 logged in (which didn't show up as a critical error on the user panel preventing the machine from being operated) in the last 10-15 days.

Looking forward to your insights.

[slimslob]

Are you working on a Black and White machine or a color MP C600?

Assuming that it is a B/W, you most likely have a toner hazing problem which will cause a build up of toner in the connector block of the charge corona creating current leakage to ground and the SC3xx errors. It can also fog both the image density and the drum potential sensors. My policy with any Martini series that was starting to under tone was to properly clean both sensors and then run ID sensor initialization. As for the corona, you may need a new one. With as old as the MP 6000 is, the plastic connector block can develop micro fractures that will result in current leakage.

[orestesp]

Are you working on a Black and White machine or a color MP C600?

Assuming that it is a B/W, you most likely have a toner hazing problem which will cause a build up of toner in the connector block of the charge corona creating current leakage to ground and the SC3xx errors. It can also fog both the image density and the drum potential sensors. My policy with any Martini series that was starting to under tone was to properly clean both sensors and then run ID sensor initialization. As for the corona, you may need a new one. With as old as the MP 6000 is, the plastic connector block can develop micro fractures that will result in current leakage.

Hey Slim, thanks for the reply.

Yes it's the B&W box. I cleaned and re-init the ID sensor couple thousand prints back, not that it was all that dirty to begin with. I also remember you saying no alcohol on the ID lens, so I've always cleaned them with a damp paper cloth. Would the cracks you mention be visible if I took out the corona to inspect it? Or I can only find out by testing with a new corona/scorotron assy?

I should also mention that the machine is at 1.3M prints.

[Luism]

Hello, you are getting the correct VSG and VSP values, which indicates that the control pattern is printing correctly on the cylinder. Have you tried the transfer belt or the complete transport of another machine?

Regards

[slimslob]

Hey Slim, thanks for the reply.

Yes it's the B&W box. I cleaned and re-init the ID sensor couple thousand prints back, not that it was all that dirty to begin with. I also remember you saying no alcohol on the ID lens, so I've always cleaned them with a damp paper cloth. Would the cracks you mention be visible if I took out the corona to inspect it? Or I can only find out by testing with a new corona/scorotron assy?

I should also mention that the machine is at 1.3M prints.

How did you clean it? If you used anything other than a soft cotton cloth slightly dampened with distilled water only or a soft bristle lens brush you may have damaged the sensor. Glass cleaners like windex will leave a soap film that you might be able to rinse off. Solvent cleaners will etch the surface of the lens and require replacement.

[orestesp]

Hello, you are getting the correct VSG and VSP values, which indicates that the control pattern is printing correctly on the cylinder. Have you tried the transfer belt or the complete transport of another machine?

Regards

check my original post

Vsp=0.41 V
Vsg=4.54 V

If I remember correctly, from what I've read Vsp should be about 1/10 of the Vsg value, which seems to be the case here.

also the transfer belt unit has been thoroughly cleaned and everything on it has been replaced late last summer.

How did you clean it? If you used anything other than a soft cotton cloth slightly dampened with distilled water only or a soft bristle lens brush you may have damaged the sensor. Glass cleaners like windex will leave a soap film that you might be able to rinse off. Solvent cleaners will etch the surface of the lens and require replacement.

just water on a paper towel. the water in my area is really soft if you're worried about mineral deposits.

[orestesp]

Also, on an unrelated note: are toners branded "NRG" really made by Ricoh?

[Luism]

That's what I'm saying, the vsg/vsp values are correct
vsp is 1/8 of vsg, that's fine
do you have the vtref and vts values? and bias values?
the seal on the images you sent do not affect the copy quality

[luca72]

Hi everyone,

Just a quick sanity check. The backstory is this: on my MP6000 I had to replace the developer early (at ~200k, 150k before yield) because the density was too low. I was also getting some shadow SC-3xx logged to the machine in that time period, unfortunately cant remember which specific ones. I'm beginning to see a deterioration in the max density the machine can produce yet again, I should also mention that every other part is original and within yield. What I mean by deterioration is that in the checker flag test pattern, I don't seem to be getting as deep a black as I can get on a MP4001 I have for office use (whose developer is past yield and I use some compatible parts since it's not a priority printer in the shop)! Of course when I had just installed the developer on the machine it was printing a very nice deep black but now after a couple tens of thousands of prints it's not as deep...

I've always followed the bulletin's instructions about thoroughly cleaning everything up and cleaning the grooves of the mag roller with a wire brush but that didn't stop it from happening before. I've also noticed that I may have attached the side seals the wrong way? I've seen some photos where the lower part of the seal seems to be tucked in inside the cavity between the mag roller and the lower metal part of the dv unit but how would that work since I assume you'd have to stick it on the mag roller which rotates? Really not sure what's the correct way since when I got the machine all the seals had deteriorated so badly and thus didn't have a reference when I was replacing them.

Here's some also related info on the issue I pulled from SP mode:

Vl=99
Vsp=0.41 V
Vsg=4.54 V
Auto Process Control is Enabled
Oh and there's also a SC-315 logged in (which didn't show up as a critical error on the user panel preventing the machine from being operated) in the last 10-15 days.

Looking forward to your insights.

in my opinion, the development unit is old, the magnet has degraded, and the prints are right to be replaced as a whole, then I would also check the toner supply clutch mechanism if it works well

[Larhal]

Also, on an unrelated note: are toners branded "NRG" really made by Ricoh?

Yes They are Ricoh.

[orestesp]

That's what I'm saying, the vsg/vsp values are correct
vsp is 1/8 of vsg, that's fine
do you have the vtref and vts values? and bias values?
the seal on the images you sent do not affect the copy quality

I was worried I had the seals installed the wrong way, which could potentially start scraping developer off the mag roller and thus gradually depleting the developer (not that I have found any evidence supporting this, but still).

Sorry indeed I misunderstood.

I was finishing replacing the gate pawl reverse exit on the duplex unit today. I made note of the following values before letting the machine run:

SP-2-220-001 Vref Manual Setting: 349 V (Initial 250)
SP-2-223-001 Vt Display: 337 V
Vsp/Vsg same as before (the machine hadn't ran)

I was getting alright results but density could be better. So I run process control (automatic adjustment of drum conditions). It ran for a while. Then I got the following values:

Vsg=3.68 V
Vsp=0.72 V
Vref Manual Setting=325 V
Vt Display=347 V

And density was even worse than before. Voids in checker flag test pattern. Very poor IQ.

Took out the drum unit. Cleaned the ID sensor (not that it was dirty but there was a small pile of toner to the left). Re-init the ID sensor. Ran automatic adjustment of drum conditions again. Got the following values:

Vsg=4.01 V
Vsp=0.27 V
Vref Manual Setting=347 V
Vt Display=337 V

Now it's back to where we started, where it's satisfactory but it could be better.

Attached are a bunch of photos, I can't see anything wrong but maybe someone more experience could spot something. The test printout in the photo is the satisfactory result I mentioned earlier, but you can see that there's clearly room for improvement.

in my opinion, the development unit is old, the magnet has degraded, and the prints are right to be replaced as a whole, then I would also check the toner supply clutch mechanism if it works well

The whole toner supply mechanism I sent away to be rebuild by a local shop I trust and I must say they did a very good job. That was done last summer as well, the machine was coding out because it wasn't feeding any toner.

Do permanent magnets lose their pull over time? The only instance I know when this happens is when they are heated above a certain temperature. Have you ever come across such an instance?

unfortunately there's no spare dv unit around for me to test, and throwing the parts canon again at it is not really feasible for me at the moment.

[slimslob]

I was worried I had the seals installed the wrong way, which could potentially start scraping developer off the mag roller and thus gradually depleting the developer (not that I have found any evidence supporting this, but still).

Mentioning depleting reminded me of one other thing that can happen to development units. Pull the first paper feed unit and check for developer on the back end. This is often caused by leakage of bearings at the back development experience unit.

[rthonpm]

Mentioning depleting reminded me of one other thing that can happen to development units. Pull the first paper feed unit and check for developer on the back end. This is often caused by leakage of bearings at the back development experience unit.

Once you hit a million pages on one of these I'd look at replacing the developer unit entirely.

[orestesp]

Mentioning depleting reminded me of one other thing that can happen to development units. Pull the first paper feed unit and check for developer on the back end. This is often caused by leakage of bearings at the back development experience unit.

when I got the machine at 900k there was no evidence of leakage in the feed units and the surrounding areas. with the first DV change I replaced all 4 bushings.

are the Vref Manual Setting and Vt Display values I'm getting good? what I don't understand is why after manually prompting the machine to run process control (which I think attempts a few times before aborting, nevertheless you get a "completed" message at the end) it runs the density into the ground.

do the dv units just crap out like that? could my ID sensor be misbehaving?

[luca72]

I was worried I had the seals installed the wrong way, which could potentially start scraping developer off the mag roller and thus gradually depleting the developer (not that I have found any evidence supporting this, but still).

Sorry indeed I misunderstood.

I was finishing replacing the gate pawl reverse exit on the duplex unit today. I made note of the following values before letting the machine run:

SP-2-220-001 Vref Manual Setting: 349 V (Initial 250)
SP-2-223-001 Vt Display: 337 V
Vsp/Vsg same as before (the machine hadn't ran)

I was getting alright results but density could be better. So I run process control (automatic adjustment of drum conditions). It ran for a while. Then I got the following values:

Vsg=3.68 V
Vsp=0.72 V
Vref Manual Setting=325 V
Vt Display=347 V

And density was even worse than before. Voids in checker flag test pattern. Very poor IQ.

Took out the drum unit. Cleaned the ID sensor (not that it was dirty but there was a small pile of toner to the left). Re-init the ID sensor. Ran automatic adjustment of drum conditions again. Got the following values:

Vsg=4.01 V
Vsp=0.27 V
Vref Manual Setting=347 V
Vt Display=337 V

Now it's back to where we started, where it's satisfactory but it could be better.

Attached are a bunch of photos, I can't see anything wrong but maybe someone more experience could spot something. The test printout in the photo is the satisfactory result I mentioned earlier, but you can see that there's clearly room for improvement.



The whole toner supply mechanism I sent away to be rebuild by a local shop I trust and I must say they did a very good job. That was done last summer as well, the machine was coding out because it wasn't feeding any toner.

Do permanent magnets lose their pull over time? The only instance I know when this happens is when they are heated above a certain temperature. Have you ever come across such an instance?

unfortunately there's no spare dv unit around for me to test, and throwing the parts canon again at it is not really feasible for me at the moment.

yes, if overheated they can lose their strength almost instantly, Under normal conditions ferrite magnets retain their magnetism for an almost unlimited period of time. However, influences such as temperature, vibrations or magnetic fields can have a negative effect on the holding force of a magnet, and as a result the magnet can lose part or all of its attractive force...let's remember that the bias balance in a photocopy machine works very precisely, an minimum unbalance in the forces is enough to create deleterious effects on the prints