How I Fixed My Printer After a Paper Jam Left It Printing Double

FIXING MY CANON PIXMA MG3620 - THE SURPRISINGLY SIMPLE SOLUTION:

I have a Pixma MG3620 that I bought for my home office a couple of years ago. It recently started eating paper. Finally, I had a nasty paper jam where the paper was sucked up inside and I couldn't reach up inside the machine to pull it out. 

I almost dismantled the thing with a hammer, until (God bless YouTube) someone showed me how to open the back to get inside. Once I figured out how to open the transport cover in the back (push down toward the arrow- see photo), I was able to extricate the paper. 

Turn the printer on its side
& press down to release
the transport mechanism cover

When I tried to print again, my printer started eating paper and no matter how many times I cleared it, it wouldn't stop eating the paper.  On a hunch I shined my flashlight down into the mechanism and spied something shiny. I made a hook out of a paper clip (see photo for how the engineering for the hook was done). I reached in, snagged the plastic thing and pulled out a small plastic bag of extra earbud covers that had apparently taken a ride up inside the printer on one of my print jobs. 

I had been so frustrated I was looking for a new printer last night. The turning point was finding out how to open the transport cover which turned out to be very very easy. They even embedded an arrow in the  cover to show which way to push it to open the paper transport mechanism.

I felt a bit stupid after I saw how it was done. So glad I don't have to buy a new printer. I'd have had to pay twice as much to replace it with the same one, Inflation has doubled the cost of the same 3 year old printer. How's that for a green new deal?

 

Where the baggie was hiding.

Once the printer is open, check here (see arrows) for paper or trash. In this photo I've got the paper transport mechanism cleared of paper but down in there where this arrow is pointing there was a glint of plastic when I aimed my flashlight at it. The trouble was now, how do I get it out of that narrow space. My fingers are too fat to fit in there.

Sooooooo, I had to fashion a highly technical tool to retrieve the bit of plastic stuck in the paper path. I did this by bending a hook into the end of a large paperclip using a pair of needle-nosed pliers I keep in my pencil box for just such emergency repair tasks (I tend to drop things down into tight places). You can see here my elaborately fashioned hook and the plastic bag of earbud bud-covers that somehow got itself sucked up inside my printer. The wife says it's an object lesson about keeping my desk clean that God had sent to me. I do not argue about these sorts of things with her. Besides, she may be right!

 

You can see the stray letters and the doubling of the text. It was all due to
smudges on the encoding strip. Not something I'd have expected.

 

Once it got to where it would print, it started printing double and throwing out random lines of characters. Here's what it looked like (above). I then printed up a test print (left). It's supposed to line all those line segments up in a straight column. It did anything but straight columns as you can see. This would never do. I began scouring the Internet to find out what might be wrong. I had more time than money for a new printer at the time, so there was sense of desperation to my search. Finally, I stumbled upon the answer.

Here's how I fixed it.

1. Unplug the printer.
2. Open the front of the printer. Shine your flashlight inside.
   
3. Find the clear plastic encoder strip. It's above and parallel to the metal bar the printer carriage rides on. It's really hard to see. You'll need a strong flashlight.
   
4. Clean the encoder strip. If the printing is wacky and aligning the print heads doesn't work, you've got smudges on the encoder strip. Use a long wet Q-tip (I didn't have one so I put a soft wet linen cloth over the end of a ruler). GENTLY rub the smudges off the plastic strip. It's these smudges, likely from your earlier efforts to dislodge the paper jam, that are distorting your image.
5. When the strip is clear, you're done. Don't press hard. Gentle back and forth wiping works. Don't go up and down. You could break it. Breaking the encoder strip, as inconsequential as it looks, will turn your $120 MG3620 into a big plastic brick.
6. Time for some housekeeping. You might while you are in there, plug the unit back in and turn it on. Have your trusty Q-tip at the ready. When the rollers spin up, use your Q-tip to clean off the dirt and ink so the rollers grab the paper better. You can also go down to the paper tray and clean the rollers in the center that grab the paper by the sheets.
7. Print a test page. Everything should look good after that.
8. If it's still a little dodgy follow the instructions for aligning the print heads. You probably did that first, but do it again. You may have bumped the printer carriage or something It's pretty easy to fix once you know what's wrong. Cleaning that plastic strip should get you fixed right up.
9. A little more housekeeping while you're at it. My wife always makes me dust things whenever I'm back there fixing connections and replacing parts. I go ahead and do it because when she can't stand it anymore, she dusts back there and then I have to spend the next couple of hours reconnecting all the wires that fell out while she was cleaning.
   

Here's the smudged encoder strip.

I had no idea a few finger smudges could mess up the printing like that. Before I started, I didn't even know printers had an encoder strip that looked like very thin strip of Scotch tape. DON'T FORGET! Be VERY, VERY gentle when you're wiping it off. Breaking that delicate strip of plastic tape will assassinate your nice printer. Given the number of printers I've worn out, I could have built a brick printer wall out of them all. I still have most of them in the forlorn hope that one day I'll fix them. Not bloody likely given how fast Windows' new versions make my lovely old printers go obsolete, but I hate to throw the old warriors out on the heap. Notice, I tend to anthropomorphize my technology. You should NOT do that unless you have a lot of storage space for old electronics..

Have a lovely day and hopefully a better one than this one started out to be. Ah, but then it ended up pretty good. There's nothing quite as satisfying as kicking a problem in its fuzzy buttocks.

© 2021 - Tom King

 P.S.

Here is the highly technical paper jam retrieval tool I made.
Above it is the baggie of buds I retrieved with it.