MP780 persistent Check Printer Press [OK] message

[panos]

Perhaps the message you get is related to ink leftovers forming a tar on the pads under the printhead parking position which may be hindering the initial movement.

If this happens to be the case, what is the solution? Challenging task of cleaning the pads?

The cleaning itself is not difficult, but opening the printer to reach them is not the easiest procedure.

I did that using these german step by step instructions http://www.druckerchannel.de/artike...fangbehaelter_fuer_ueberschuessige_tinte_voll (you can use google translate)

I wonder if there is any way to inspect the pads in the parking area before opening the printer. Perhaps taking a photo with a small mobile phone would help.

 

[embguy]

I found the MP780 service manual. Do a google search for the Canon_PIXMA_MP750_MP780_SERVICE_MANUAL.rar file.

I don't have EEPROM CLEAR option, so I followed these alternative instructions, but it didn't help

1. Service menu: Menu -> Scan -> Copy -> Scan (one at a time in sequence)
2. Select TEST MODE
3. Select [8] ETC..
4. Select [4] EEPROM CLEAR
5. Select [1] INK COUNT
6. Press the [OK] button.
7. Press the [Stop/Reset] button (returns you to the TEST MOD sub-menu))
8. press the [ON/OFF] button (which resets the printer)

 

[CPngN]

You can get into service mode and print the content of the EEPROM.
Look for D = xxx.x which is the waste ink amount in %
If it is not closed to 100%, you can eliminate the waste tank full possibility.

1. Turn printer off.
2. Press & hold Stop/Reset button.
3. Press & hold power button.
4. Release Stop/Reset button. Press Stop/Reset button twice.
5. Release power button. You are in service mode.
EEPROM dump: Make sure you have paper on the paper tray
6. Press Stop/Reset button twice
7. Press power button once.
8. Press power button to get out of service mode.

I did this or whatever was necessary on the MP780 to get this info sheet and have D=029.1, so I guess I have used about 29% of my waste ink reservoir..? I'm getting an overheated head error (error number 5200) after printing for a while... it's so bad that I can only print a few pages now at most before it craps out. Since it's not my waste ink overflowing, I'm guessing I probably just need to remove the print head and clean. Or maybe I should try a cleaning cycle, since I rarely have needed or used them in the past few years I've had this thing..?

I see some people saying clean and deep clean cycles eat a lot of ink for something you can fix by just removing built up junk around the head. I print a few CDs every month but otherwise nothing special. I think I'd like to just pop the head out, throw the carts in a bag, and clean it up regardless, but I'm wondering if there's any photo-blog or video of doing this specifically on the MP780. I just looked inside and it appears that there's just a gray lever you can flip up and then I'm guessing/wondering if you can just pop the carts out and then the head comes out easily or...what? Everything inside the printer is still clean and well lubricated; no splattered ink or paper bits. So I'm banking on a gunked up head.

Anyone have any tips/links to the removal of the print head? I'd ask for cleaning instructions but there's already plenty of help on that part.. I just want to verify the best way to remove the print head. Thanks!

 

[ghwellsjr]

First off, I have stated that deep clean cycles waste a lot of ink, not the regular clean cycles. But you need to do nozzle checks between cleaning cycles to see if things are getting better. However, you haven't stated that you even have a problem with clogged nozzles--just the warning that your head is over heating. But the major cause of the head over heating is a lack of ink flowing through the nozzles, which is what keeps the head cool. There is a real danger of damaging the print head if you don't have ink flow.

So the first thing you need to do is a nozzle check to see if you have ink flowing through all the nozzles. Do that and report back what you find for the next step.

I do not recommend that you remove your print head to clean it. You should let your printer try to clean it, there is less risk of damaging your print head.

 

[CPngN]

Well I spoke too early, as I had forgotten that the print head comes out super easy if you just take the tanks out first ... it was one of the main reasons I switched to Canon. I've gone through 2 or 3 nice Epson photo printers in the past, having torn them apart to clean their damn print heads, and eventually just getting sick of doing that. Of course this is the first serious problem I've had with the Canon, as I don't let it sit near as long between prints now that I have a multifunction that can print on CDs.

ANYway, since the overheat was no longer just an inconvenience, it was getting to the point that the printer would just give up, I cleaned it anyway. Thanks to all for the previous "alcohol can be too strong" and "coffee-filter instead of paper towels" tips. I also quickly understood the suggestion of a compressed air to straw to printhead nozzle and I have to say that really helped squeeze out ink in the print head. But I think I wasted that ink, as everything was printing fine aside from the overheat.

After popping everything back in, I think the printer did an initial clean automatically, as it picked up an old, stuck print job and started printing. Then it slowed to a crawl with the overheat thing again. Damn, it IS shot! ... or not! Photo black was low but not out - looked like it had a few days worth in there. Well, it only looked that way. I think you hit the main problem above... lack of good ink flow was allowing it to work slightly, but not enough to stay cool. I decided before I drop $60 on a new head I'd at least try one cleaning cycle. I did some nozzle checks and a few were clogged, so I put a new ink cart in "early" and went ahead and did a deep cycle. Another test showed everything was flowing. I went back to my long document and printed the rest flawlessly and at normal speed. ..then I had to leave, so I haven't been able to test it more. But I think the lack of enough black was causing it to overheat. I think from here on out I'll try not to use up every last drop of ink, and consider myself lucky if it's back to like-new and not already ruined (so far it seems to have survived just fine!).

I must say that the reason I bailed from Epson and went with Canon (user removeable print head, plus of course the benefits of a multifunction) have definitely paid off. I have been more than happy with this thing after getting CD printing to work (shame it has to be a "hack" in America).

So, in the end, all my babbling boils down to this: if you're having strange problems and an ink cart is getting low, try a new one first. It may have just dried up a bit early, and could ruin more expensive parts if you force it to keep printing!

Oh, also thanks to whoever suggested printing the EEPROM info and checking the waste ink level. I was about to buy new pads and go through that ordeal, then found out I'm only at 29%! Hooray for that.

 

[CPngN]

I jinxed myself with the "too early" above.. because now I've definitely posted too early, as today it's back to overheating. Even the black and white EEPROM printing is going slow.

Does anyone know if these temps are high? I'm assuming Celsius based on env temp of 28, which would mean they are WAY hot, but why? It looks perfectly new - nothign is blow, and it's all nice and clean again. Do print heads just crap out sometimes after a number of years?

EEPROM line 1: MP780 V1.18 IF(USB1=1 1284=0) D=030.6 ST=2013/05/08-16:05
blahblahblah
Head TempBK=70.0 Head TempC=72.0 Env Temp=28.0 FF(07 07 FF)

If those are Celsius, env temp of 28 is 82.4F! It's not that warm in here, closer to 72, but ok. However, that makes 70.0C... 158F! I suppose for heating tiny drops of ink that might not be that bad, but I have no idea if it's within normal range or what.

Anyone have any ideas... or know of a cheap place to get MP780 print heads?

Thanks!

 

[ghwellsjr]

The best place to get print heads is from the manufacturer. It might be cheaper to get one through a local authorized Canon repair center if you're willing to wait for them to ship it with other parts. They are also available on eBay. There are several other Canon printers that use the same print head, the iP4000, MP750 and MP760. Maybe you could find a used printer that you could borrow the head for test purposes or buy one cheap. Lots of people find these printers at yard sales, thrift shops and on Craig's List.

 

[irha]

I finally found enough time to fix my printer. I followed the instructions at the German page pointed to me in one of the earlier posts (I used both google and bablefish translations) and disassembled the printer to look at the waste ink tank and any obstructions.

What I found is that the waste ink sponge is mostly white, except for the area that is far left (which is probably where the ink gets emptied). In any case, my problem wasn't waste ink tank, as resetting the counter didn't fix the error. When I looked for obstructions, all that I could find is a displaced small sponge on the right side (not sure if it was obstructing something, or it got displaced while disassembling), and a small hair. I took care of them and assembled it back, and after a couple of cleaning cycles the printer is back to life now. One more thing, I also removed the battery backup for a few hours to clear any error state, in case the printer is stuck in a bad state.

One last thing, I managed to disassemble and assemble it back without breaking any functionality. The only thing that actually broke was a small piece on a clip that guides a few wires to the motherboard. This caused it to not sit tight, but I used a tape to fix it in place and the tape is not even visible after assembling fully. A tribute to the nice instructions from the German website.

Thanks to all on this forum for providing me with helpful information.

 

[CPngN]

Update on me. I finally ordered a print head from eBay from Tec2Go because they didn't charge shipping AND tax. There aren't exactly too many places to find this print head in the first place, and most want $60-70 plus tax plus $10 shipping. I started to consider just upgrading to a new printer, but the new equivalents that I'd have to go with are still in the $250 range, so it's worth keeping this puppy going to me.

When I popped the old one out it had ink spattered all over the bottom, but I think failed when I removed the ceramic board the heads are attached to and didn't clean everything out perfect before screwing it back down.. so, I'd advise never loosen those 2 screws, or be prepared to really clean everything out hard core. I also couldn't lift it back easily without it sounding like something was cracking.

Anyway, the new one is in. It seems to do it's own initialization to get the ink flowing as I didn't have to run anything but a head alignment and a nozzle check to see everything was already flowing perfect. After realizing I've had this printer for many years and reading someone say that the printheads aren't designed to live longer than 20 cartridge lives, I'm considering this normal long term maintenance, like changing a fuel filter or something.

I'd also suggest changing carts as soon as it starts warning you and the main ink well is dry. I've pushed every last ink out of them before, hitting OK to continue with a 99% dry cart before, and I fear that while it technically printed, I slowly overheated and ruined the head. And it's not damage that you can see... the head will look fine with the naked eye.

Hope this helps someone and encourages you to get a new print head if you've run out of options. If you're having difficulty or overheating and your printer is old, get a new head before you toss the whole machine! It's one of the top benefits of a Canon printer - easy head replacement. Don't miss you at all, Epson!

 

[ghwellsjr]

This is great! Two malfunctioning MP780's brought back to life.

Irha's problem was a purge pad that had come out of its rubber tray and putting it back solved the problem.

CPngN's problem was an overheating print head due to squeezing the last drop of ink out of the cartridges. One question I have is that you mentioned at some point you took apart the print head to clean it and didn't get it back together again correctly. When did you do this? Was it after you had already given up on it and ordered a new one or was this the reason you ordered a new one?