micro banding

Saphire

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I bought new qy6-0076 print head for my I9950. Yesterday I have installed it in printer. Before installing it I do nozzle check with old one and it was all right. When I install new one there was no yellow cyan and magenta at all on nozzle check. I was looking on interne and seller advice me that problem is in purge unit. I didn't belive and i put old one again and same problem.then I try to clean purge unit. I take off small plastic where y,m and cyan rest I clean plastic and I put on purge unit where plastic sit a small amount of Windex. I put back plastic and do regular cleaning and do nozzle check and then is little bit shown yellow and cyan. I repeat procedure 3 times, still no magenta to shown and yellow and cyan are only about 40% shown on nozzle check.then I was thinking maybe the head nozzles are cloged .. and I clean new head put it back again same thing no yellow magneta and cyan at all. I m very nervous becouse I was cleaning new head, two times putting it in the printer. And now I don't have a printer. Can I put printer back on live and how? I boght head new one from Germany c1. Not China.
 

PeterBJ

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Could you upload some nozzle checks? Both nozzle check with the old print head before the exchange and after reinstalling the old print head after trying the new print head are needed. Also upload nozzle checks from the new print head before and after cleaning the purge unit.

These nozzle checks might help determining whether the new print head is defective or the purge unit is causing the problem.
 

stratman

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I bought new qy6-0076 print head for my I9950. Yesterday I have installed it in printer. Before installing it I do nozzle check with old one and it was all right.
If the old print head had a proper nozzle check then why did you install a new print head?

When I install new one there was no yellow cyan and magenta at all on nozzle check. I was looking on interne and seller advice me that problem is in purge unit. I didn't belive and i put old one again and same problem.
To clarify, you put the old print head back in and the nozzle check was missing Yellow, Cyan and Magenta?

If this is so, then the sequence of events is the old print head printed a proper nozzle check, the new print head failed a nozzle check and then the old print head failed a nozzle check, and you did nothing else up to this point to the printer except change print heads and print nozzle checks?

then I try to clean purge unit. I take off small plastic where y,m and cyan rest I clean plastic and I put on purge unit where plastic sit a small amount of Windex. I put back plastic and do regular cleaning and do nozzle check and then is little bit shown yellow and cyan. I repeat procedure 3 times, still no magenta to shown and yellow and cyan are only about 40% shown on nozzle check.
Have you tested the purge system yet? If not then try the following:

Use a syringe/needle, soda straw, long eye dropper or some other implement FLOOD water on top of the purge pads. Water should POOL on top of the 2 pads. It takes more than a couple of drops to FLOOD the purge pads. The purge pads are located to the extreme right as you look into the inside of the printer. When the printer is idle or powered off, the print head rests above the purge pads. Open the lid and you will see the print head come to and stop in the middle, like when you change cartridges. Now use a flashlight to see the pads to the right. FLOOD the purge pads making sure you see a pool of water above them then close the lid and perform a simple cleaning. Open the lid and look to see if the water is now gone (the pads may even look a little less blackish). Report if you are unable to FLOOD the pads, if the POOLED water doesn't go away. Report your experience - if it worked as expected or not.

then I was thinking maybe the head nozzles are cloged .. and I clean new head put it back again same thing no yellow magneta and cyan at all. I m very nervous becouse I was cleaning new head, two times putting it in the printer.
How did you clean the print head?

It is possible the print head may be damaged from cleaning, such as moisture remaining on the electronics of the print head when you reinstall it and then try to use it.

I boght head new one from Germany c1. Not China.
Any possibility this print head was a refurbished unit? Country origin of sale is not a guarantee of honesty.


Have you tried new OEM cartridges, or known working cartridges, other than the ones in the printer when you began trying the new print head? In other words, could this be ink starvation from the cartridges?
 

martin0reg

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In i9950 can be seen lines on areas of plain color, for example blue sky or asphalt everything else is just fine. Is that normal or problem with ink flow. Nozzle check and head alignment is just fine. That lines I can only see when i look close on picture. That irritates me a lot becouse complex details are fine but sky not.
Years ago I had a S9000 then a i9100. With the i9100 I had this annoying micro banding too. Do a search on s9000 i9100 or i9950 + microbanding and you will find several approaches to the issue (printer settings and speed, sort of paper and paper feed, etc...) ...nothing really worked for me though.

Hopefully your printer was not damaged while changing the printhead and you can get it back to work with the old ph...I would suspect rather problems with ink flow than a clog, if there was none before..
 

turbguy

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If the old print head had a proper nozzle check then why did you install a new print head?

He was suffering from streaking/fine lines in blue sky with the "old" head.

Does an i9950 have two purge pads (like an i9900)? If so, I would also suspect the purge unit...particulary of the driver offers a cleaning "choice" of colors in which one choice include ONLY magenta, cyan, and yellow.

Being an 8 color printer, what's the "missing color" in the cleaning "choice"?

Additionally, upon re-installing the purge pad ceramic ("plastic") insert, was great care used to assure the surrounding sealing gasket is undisturbed/undistorted an all the little tabs (four tabs?) are resting atop the insert?
 

The Hat

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@turbguy you may be onto something because this printer has a tendency of blowing off a hose on the purge unit if it gets overworked.

Group 1 :- 6BK 6R 6G 6PC 6PM
Group 2 :- 6C 6M 6Y.
 

Saphire

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Yes he have two purge units and I think that that one for yellow magenta and cyan is not working well. Thank for replies. When I put Windex in purge place where sit y,c,m liquid just go down. In other purge unit liquid stay. So what I had read on this webpage something is not good with that purge place. Also I soaked the head in Windex because head was clogged only that three colors y.m.cy. I can show nozzle check. I will put later. Now is situation Magenta is perfectly ok, yellow is fighting sometimes is perfectly sometime is 5o% or not at all. I do many cleaning cycles for that group of color. So what I know now is that cyan is clogged because whean I wash last time a head and I put Windex on top of all color outside of printer all liquid has gone down except cyan not a 1mm. I agree with Hat that printer has overworked when I put new head and some hole brake. Or the purge unit didn't work well and before. Now I have two problems fix clogged cyan and fix purge unit. So guys please help. Also the amount of ink is not going down of magenta and yellow when I do cleaning cycels. or inks are genuine canon new one full.
 

turbguy

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If your test of the purge pad for Cyan, Magenta, and Yellow is that you cannot sustain a pool of standing fluid on the pad, then there is a leak in the purge system that must be repaired. It could be as simple as hose has come off a nipple below the pad. Easy to fix IF you can get at it...

Typically, accessing the purge unit for repairs requires considerable printer disassembly. I will let others comment about that.
 

The Hat

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I have a similar printer to the i9900 and you’ll need to remove the top cover and unscrew about 6 screws to remove the chassis from the bottom casing then you can gain access to the purge unit.
The screws are difficult to reach; you may need a very long crosshead screwdriver (Magnetic if possible)
 

PeterBJ

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It seems that the only difference between the i9900 and the i9950 is that i9950 is for the European market and has CD print capability.

This post has links to the service manual and parts catalog.

Druckerchannel.de has an instruction for disassembly of the older S and i series of printers here. And here is a Google translation. The instruction is for A4 printers, but I think the printers are similar in design.

I have an i965, which failed to prime the print head after a cartridge change. The cartridges were OK, they worked well in other printers. I then did turbguy's purge unit test and it was a fail, water drained away from the purge pad.

Like with the i865 mentioned by turbguy the cause of the problem was a hose that had become disconnected. See this post for pictures of the purge unit.

I removed the printer chassis from the casing and placed it on some newspapers. I could then localize the leakage. I was able to reconnect the hose, I guess I used long nose pliers.

Normally a malfunctioning purge unit is bad news, but in this case it could mean that the new print head is perfectly OK, but fails to print because it is not primed by the purge unit. Hopefully it is only a disconnected hose causing the problems. @turbguy , I wonder if the loose connection is a problem with all i-series printers or maybe caused by the hoses lose elasticity due to old age? Is there any suitable replacement hose material available? I guess these printers are around 10 years old now?
 
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