Two issues with Canon s750

drfugawe

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Greetings,
I've got two problems with my Canon S750, a machine I've never had any problems with for many years now. Recently, it started making a hellacious noise each time I would try to print - when I opened the cover, I noticed that the carrage was not moving to the middle position, and the noise was coming from that area - I mildly tried to move it, but not with much force. Is this a common problem? Does it sound fatal? My local computer guy didn't want to even see it - he says printers are so cheap now, that repairs are not warranted. But I like these older printers because I can use 3rd party cartridges or even refill them myself - so I'd like to fix it if possible. Have I given enough info for anyone to suggest a fix?

Thanks much - look forward to hearing something.
jm
 

Trigger 37

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drfugawe,... Just open the cover and then pull the power cord from the rear of the printer. Now the carriage asm is free to move left and right. Move it out of the way so you can get at the purge area. What you want to do is to see if some part of the purge unit is jammed. This section contains wiper blades that wipe the bottom of the head to clean off excess ink. Clean off as much ink as you can and make sure the wiper asm is not stuck extended. There are gears in this unit that move the blades up and back and if the gears slip out of track, you will have all kinds of noise.

To get at the purge unit you have to remove the covers and take out the main chassis from the base, and then you can get at the purge unit to take it out. Once out it is even more of a job to take it apart and re-seat the gears. If you really want to do it I sell Repair Manuals for most all of the Canon printers that show the details on how to do this and to maintain your printer for years to come.

The reason they want you to buy a new printer is becuase the new ink carts are chipped and you have to use their expensive inks unless you refill your own ink carts. Your printer is worth more than a new one because it uses inexpensive ink carts.
 

drfugawe

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Oh sorry - I forgot to mention the 2nd issue I'm having - it's not directly with the S750 but with the fact that of course, I've just bought a huge supply of ink cartridges for the S750 (BCI-3e). Since I may need another printer, I have been checking out eBay for a potential replacement printer that would still allow for the use of refilled cartridges, and I keep running into printers that are supposed to be using the BCI-3e cartridge, but instead they're using a BCI-6 cartridge. Is this the same cartridge with two different names, or is the BCI-6 completely different than the BCI-3e?
jm
 

drfugawe

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Trigger,
How much is the repair manual for the S750?
thanx,
jm
 

Trigger 37

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drfugawe,... All of my manuals are $25 + $3.50 for shipping. I still have a little bit of work to do on the S600, S520, S820, S830, S900 Manual and once it is done I will put it on eBay. The S750 is no different than these and I will update the manual to include the s750. If you can't wait, send me an email and we can work it out.

As far as the Canon BCI-3 and the BCI-6, you don't have to worry about anything. They are identical and always have been. At one time Canon was putting different ink in these but eventually gave that up. However they didn't want to confuse customers so they never told anyone, as 1000's of people had ink carts for both types of printers,... so like most good companies, they said nothing. I have repaired and used BCI-3/-6 ink cartridges in all kinds of Canon printers and there is no difference.
 

drfugawe

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Hey Trigger,
Tried working on the Canon S750 today, and followed your instructions - but when I pulled the power cord from the printer, the printhead still would not budge. Is that indicitive of other problems? The lights are blinking 3 orange with 3 green between, and then a longer green. Isn't that the code for empty ink? But I've got all full ones in there.

Any ideas?

Thanks, john
 

Trigger 37

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drfugawe,... The first line of my post said
Just open the cover and then pull the power cord from the rear of the printer
. It sounds like you did not open the cover of the printer. When you open the cover the printhead should move to the center, and that is when you pull the power cord. The printhead has to move away from the park position and then when the POWER is off, the head is free to move.

The 3 orange/green lights is a error signal which is basically a paper jam, or that the paper feed unit is not feeding paper, or that the purge station cycle is not working correctly. The actual error code is "Abnormal Line feed encoder signal". The Service manual also "Implies" that this could be a logic board problem, or anything in that path. Since the original symptom you mentioned was the loud grinding nose and the head will not move from the park position, it is probably the purge unit. This is the unit that "Lockes the printhead" in the home position. If this unit has a broken or dis-engaged gear, the head will remain locked in position. The purge unit must cycle one revolution to lower the locking tab. If a gear is back, it can't cycle. The is a photocell in the back of the purge unit which monitors the position of the purge unit and signals this to the logic board. This way the logic knows what is working and what is not.

Unplug the power cord. To get the top cover off, there are two tabs that lock the top cover in place. These are located on each end near the back. Typically you can use a flat blade screw driver to release the catch that holds the top locked in place. One released on one side, the top should pop up about 1/4". When the other side is released, the cover should come off. Once the cover is off, you can see the purge unit. The picture below is a "Clean Purge Unit".




On the right front you can see the small DC motor that drives the purge unit. Directly behind it is a large while nylon gear that drives the rest of the unit. Use a small flat blade screw driver to rotate the gear towards the front or motor. This will turn the gear in a counter-clockwise rotation. You can only turn this gear by turning one or two teeth at a time so do it slowly. At it turns the locking level, which is directly back from the large tooth gear will begin to lower. Once it is lowered you can move the carriage asm. Rotate the wheel until you see the purge unit cycle all the way through one revolution. Since the Carriage should be out of your way now, you should be able to see some part of the problem, i.e., some gear is not engaged or something is broken.

If is seems to work ok,.. you can plug the power back in and turn the printer on. It should run through a normal cycle and you should see if anything is broken. If you can, try and print something to repeat the grinding noise you normally hear.
 

drfugawe

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Trigger,
First I'd like to thank you for such precise instuctions, for when someone as inept as I can follow them successfully, they are good! I did exactly as you suggested, plugged the unit back in, and the first time it ran through the cycle, it did make a strange noise, but I was able to get it to print several pages, and I have not heard any strange noises since the first sheet. And it may be my imagination, but it also seems to printing faster than it ever has (it had the habit of going through several "practice" warmups previously, which I no longer notice it doing - but then maybe it only did that when it was "cold" - we'll see.).

Thank you very much for your good help - it is much appreciated.
(and yes, I did have the cover off initially when the carrage still would not move - when someone goes to the trouble to give me detailed instructions, I am not going to insult that effort by not following it - thanks again for your excellent assistance.)
john
 

Trigger 37

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drfugawe,...I'm very glad to hear things worked out. But if you don't mind, I would like some more details from you on what you found and exactly what you did. Was it just that the purge unit was stuck and you freed it. What was the final problem and what did you do to fix it. This is very criitical as many of the supporters of this web site provide the best information we can, but we also need feedback on specifics. This will help us be more specific then next time around.

Good work in getting done.
 

drfugawe

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Hey Trigger,
Well, I really didn't do much, since I have a healthy fear of making things worse - I inspected all the gears I could see, and nothing looked wrong. Then I simply worked the large white plastic gear to the left of the purge motor counter-clockwise until it had moved everything through a complete cycle - then I plugged it back in and turned it on - on it's initial warmup, it made some noise, but it didn't sound quite as loud as when it was truly stuck. But it did complete the warmup, so I shut it off and turned it back on again - and this time there was no strange noise. So I took it back into its normal home next to the computer, hooked it back up, and printed off sev pages - absolutely perfect! And as I mentioned in my last post, this printer has always taken at least 45-60 seconds to go through multiple cycles before it finally printed the first page - however now it is printing almost immediately. Strange.

While I had the unit open, I noticed it was pretty dirty around the print head area, and I suspect that there is usual and customary maintenance that I should be doing - so I'll do some research today on what that is and I'll implement it.

Thanks again, Trigger.
john
 
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