Canon Waste Ink & Power On/off

[Trigger 37]

I've just finished servicing 5 different Canon printers. A i550, i850,i860, Ip5000, and an MP730. All of them are back in excellent condition. Each time after fixing a unit, I would clean it, clean the ink pads, clean the Purge unit, and then test it all as much as I could while I had it disassembled. Each time I did a power ON, the unit would go through a complete purge cycle and dump ink out on my work space. I soon learned to set that section of the main Carriage assembly on paper towels to catch the ink. I calculate that each purge cycle dumped about 3/4 of a teaspoon. In reading the Service Manuals it lists all the amount of ink that are purged in the many different types of cleaning cycles and when it decides to clean. Most are based on time, i.e., how many hours since the last cleaning. Some are after either or both of replacing a printhead or ink cart.

The Manual cleaning dumps 0.14 ml of blk and 0.5 ml of each color (that seems like a lot). The Deep cleaning dumps 1.58 ml Black and 1.0 ml of each color. If you think about it, most of the ink carts only hold 14 ml of ink. The manual does not say one word about how much ink is dumped at each power on cycle. It also counts both black and color dots, and after some unspecified amount does a dump equal to manual cleaning.

Now in all of these printers I worked on, not one was because of a "Waste Ink Error" condition. All of them had ink pads that were saturated directly below the Purge unit, but most of the time very little ink had "Wicked" into the other pads. They were all white and new on the left side.

Here are the key questions for this post. Is it better to leave the power ON all the time or turn it On and Off each day. It seems to me that it is best to leave the power on as I believe this will minimize the cleaning cycles. Also, being a Computer Engineer and working in Design and Development for 33 years, I know the failure rate of electronic components is much higher due to power ON/Off cycles. The most destructive thing that can be done to a silicon IC, is to power it on/off. Each cycle heats up the chip and then it cools as the power goes off. The causes expansion and contraction of all the connections and they eventually fracture and become open. When the life of Integrated Circuits is specified by Designers, it is stated in the total number of power ON/Off cycles. This is not to say that if you leave the power on forever that the chip will not fail. Each time a chip does what it has to do, the circuits inside are turned on and off millions of times. These are very small changes in power,...but they are changes, and they add up,... but no where near as much as the basic substrate heating and cooling.

The Canon cleaning cycles have a very strange working on the cleaning cycles that are based on time. For example, for Timing cleaning cycle #1, is says, "If 12 to 60 hours has elapsed since the previous black cleaning till the start of the next printing". So this says, if you've had your printer turned off for 2 days and then you turn it on and execute a print, it will do a cleaning first and will use 0.14ml of black and 0.5 ml of each color. There are 10 timing periods that measure the time from the last cleaning up until as much as one year (8,640 hours)

Last major question,.. Does any one think that an External Waste ink CUP would work for Canon printers. In all the Canon printers I have repaired. all of the Purge units were 98% identical. There is a purge tube out of the bottom for black and another one for all colors. The purge unit has a valve inside that cycles from sucking ink out of the black cap and then over to the color cap. To make an effective external waste ink cup, these two tubes would have to either run to an external cup and be combined into one tube and run out the back. The problem is these current tubes exit out of the bottom of the Purge unit which is within 1/4 inch of the bottom of the printer. It would be very difficult to get this out the back of a printer without elevating the tubes. This could cause a lot of clogs as when I have seen the purge unit work, the ink comes out more like a dog drooling than being pumped.

So the question is, has anyone ever made an external waste ink cup for a Canon printer?

 

[ghwellsjr]

I have always thought that it was best to leave a printer on, mainly to avoid the cleaning that happens every time you turn it on, but I didn't realize it would do additional cleanings. I know that under normal circumstances, like when you need to replace two cartridges and you do them one at a time, the printer will not do a cleaning cycle for each one, and it fact it waits until you attempt to print something before it actually does the cleaning cycle. So my question is, if you let your printer sit powered on for months, will it do several cleaning cycles during that period of time or does it wait and do just one before you get ready to print the next time?

 

[stratman]

Excellent post Trigger 37.

I have both turned off after use as well as kept my Canon MP 830 printer on all the time to see if there was a difference. What I have noticed is that turning the printer on and off will cause what sounds like an ink dump (cleaning) when the printer is first turned on again. No big news there. What is interesting is that the printer will on rare occassions do another cleaning cycle after I send a print job to the printer but before printing the task. This can happen very soon after initially turning on the printer. I was amazed to see the printer do two cleaning cycles so close to one another.

When keeping the printer turned on, I have noticed that the printer will on occassion spontaneously (I'm not doing anything with the printer) do a cleaning cycle despite not being used for some time. It only makes sense that Canon built into their ROM a counter of time, as well as printhead firings, from which the printer will initiate a cleaning cycle. While wasting ink, the cleanings will decrease printing problems and calls to tech support.

I also enquired a long time ago about a waste cup for the MP 830 like you read about for Epson printers. Seems that the Canon printer's "guts" are intimately connected to the exterior "box" such that you can not just take out the insides without disassembly of the support structures, ie you can't just remove a panel and divert the ink externally like with Epson's. I did not pursue this topic further.

 

[Trigger 37]

Stratman, I've taken apart about 10 i series printers and a couple of Multifunction MP730's. You won't believe how much they are the same when you finally get down to the basic Carriage Assembly. In the very bottom, where the waste ink pads are located, there are cavities where the ink pads set. These cavities have plastic walls about 1/2" high up to 3/4" high around the waste ink pads. Directly below the Purge Unit is the absolute bottom of the base and this is where the ink is dumped. It then floods the ink pad around that point and when it gets saturated, ink "wicked higher to the next pad. However, the ink never gets high enough to overflow the first wall.

To get a "Tube" out of that area, either you could have to cut through that wall or pass over the top of it. Behind that wall are typically other walls before you can get to the back of the printer. The print unit sets on the bottom of the case in between several walls.

Here is one way I think it would work. First I would have to find a very small "T" connector. Something like I use in the garden for miniature sprinkler heads. It is like 1/4" black tubing. I think the clear tubes coming out of the Purge unit would fit into the 1/4" tubing. Then this tubing would be connected into one of their "T"'s. Then the new single 1/4" tube can be routed around everything in the bottom and holes would have to be cut into the wall cavities to get the tube to the rear of the printer. I would then mount the printer on a 3/4" frame of wood to raise it up that much. This would provide a better gravity flow of the ink so it will actually drain out of the printer into some kind of plastic container that is sealed from leaking. As I have said before, I just don't feel the Purge unit has sufficient force to move ink all the way out of the printer. The drain tube would always have to stay lower than the Purge unit exit port or ink would back up and clog all exits.

Since I still have about 5 more printers to work on and take apart, I'll check them out to see exactly what would have to be done to each to get a tube out. Then I have to find some kind of bottle to catch the ink. It would be better if it was a shallow food container, about 4" square and only 1" tall. That should hold enough ink to last a year.

As far as leaving the printer on,.. that is the way I'm going. The tables in the Service Manuals have 10 different stages of time measure that go from 12 hours up to one year. At 10 different points in that period of time between the last time you printed something, it will change the "AMOUNT" of ink that it purges when it does a cleaning cycle, and I suspect that it waits and does a second cleaning cycle on some occasions. Many people, including myself, have confirmed that printers will do a cleaning cycle each time it is turned on. The table shows that if no printing has taken place in the last 12 hours, it will do a cleaning cycle,..but it is supposed to wait until there is a print request,... not just a power on cycle. However, I've seen it too many times dump ink on my table just because I powered on the unit to check the levels of the ink.

I welcome any comments.

 

[stratman]

Thanks for the info Trigger 37.

Do you or anyone else have an idea of how many ml's of ink used in printing before one should be concerned about problems with the waste pads in a Canon IP/MP printer?

 

[Trigger 37]

stratman, I think the ink pads will hold a lot of ink,...so the main worry is when will the "Waste Ink Pad" devil show up and lock you out of your printer. It will probably be just the time when you have to get a 25 page grant paper printed for your daughters PHD credentials. You really should not let things go this far. I suggest, as my new Manual will explain, everyone should schedule a "Once a Year" PM, or what is know in most industries as "Preventative Maintenance". That is, plan to take your printer apart to clean the printhead, clean the ink pads and all the extra ink in the bottom of your printer, clean out your ink carts and totally refurbish them (or replace them), check all the gears and shafts for proper grease, clean out all small pieces of paper, dust, spiders, hair, and then print out all the EEprom data so you can see just how many pages, dots, etc. you've printed, then reset your EEprom and the waste ink counter. Now you are good to go for another year. Wasn't that simple.

Back to your original question,.. The Canon manuals tell the service people to "replace the waste ink pads if the waste ink value is over 7%. If it has reached 95% it will shut the printer down. No where does it tell anyone how many ml =100% is, or how much 7% is. Remember, if a printer is taken into Canon for some warranty problem and the service tech fixes it, the instructions in the manuals tell him to replace the waste pads, at Canon's cost, if the waste counter is over 7%. In the listing of the EEprom print out. The first 3 things printed are,... printer model number, Version, waste ink count. It is the first thing they look at.

 

[WhiteDog]

Allow me to add to the complexity by asking about "auto power on" status. I use that with my i9900 and it works great and I get very few cleaning cycles. It is located in settings.

 

[Trigger 37]

WhiteDog,... Love your cute face and furrrrrrr. Anyway, I also liked the "AutoPower off" function. I used it on my i560 that I had for 3 years and it worked great. But now that I look back and remember, I would do a lot of work in the evening and create documents and do email, so every now and then I would print something, so the printer would power on and go through some kind of cycle and finally printed. Then I would get busy reading or doing something else, like editing a DVD video,.. and pretty soon it would auto power down and go through some kind of cycle. So it would power on/off maybe 2-3 times a night. Some nights it would stay powered off. The question is two fold,... 1. Was it wasting ink doing extra parking/Purge cycles? 2. Was it stressing the electronics with more power on/off cycles?

What I'm trying to figure out,... would it just be better to leave it on all the time? This would eliminate the power stress cycles on the electronics for sure, ... and maybe cut down on the extra cleaning cycles and wasted ink. I believe the best way to keep a printer working good is to print something with it everyday or as often as you can. My original i560 worked great for the 3 years I had it and was working even better when I sold it this year for almost twice what I paid for it. Why,..???? I used it almost every day. However, I did not use it excessively,... I mean I didn't print 60 pages a day. At the most I would do a couple of 60 page PHD grant proposals when my daughter came at Xmas,.. but mostly it was just one or two documents, emails, or some Photo greeting cards.