Canon MP780 - ADF problem

[roland6543]

My ADF is not working properly. When try to copy a page (pages) using the ADF, frequently the printed page begins printing halfway down i.e. the top half is blank and the bottom half is "cut-off" - it then gives me a "paper too long" error.

Also, when when the paper cartridge is empty, and I load more paper, then it tries to clear the ADF, but returns an error. The only option is to cold power cycle the printer in order to clear the error.

From time to time, the problem just "goes away" but after using the ADF for a few pages, it returns.

To me it seems that the way the front edge of the paper is recognized by the ADF is faulty, but I'm not sure.

I wanted to open the ADF to establish if I could see anything obviously mechanically faulty, but I cant figure out how to open the ADF.

Advice and tips welcome.

 

[Smile]

I would say you have paper sensor problem.

 

[roland6543]

Do you know which part does the sensing i.e. where is it located? Any advice for how to fix it?

 

[roland6543]

Hi all,

Apologise if I seem pushy, but since there has been limited response to this post, does it mean that there is little experience with adf repairs? Can one buy an adf anywhere and what would be the ballpark price?

 

[jflan]

PM Trigger 37, I beleive he's worked on MP780's

 

[websnail]

If you want a compatible ADF I'd be happy to ship you the one from the dead unit I haven't dumped yet... You'd just need to pay the postage.

It's an MP750 but it should be the same as the MP780 as there's no different in functionality scanning wise.

 

[Trigger 37]

Roland,... The MP780 is the upgraded version of the mp730, and I have a lot of experience with the MP730. I don't have one of the MP780's but I have the detailed pictures of the guts.

When you say you can't get the ADF open, I can't understand what you mean. If you have the User's Guide, it will show you how to open the ADF to clear any kind of paper jam. Anyway, just lift up on the ADF cover where the "Grasp" point is located. It is just a little difficult as it has a snap on each side to keep in locked in place durning normal operation. ONce you have it open all you can do from here is to check all of the rollers for any kind of paper jam or to look for any roller that looks out of place. Carefully rotate the rollers if you can and see if they turn up some more bits of paper. They may not rotate so don't force them. If they appears sticky or dirty, use just a damp wash cloth and wipe them off. Try and clean the full feed roller. Check the paper position sensor and verify that it can easily move and can detect paper in the ADF.

Here is the instruction on cleaning the ADF directly out of the Service Manual.


Follow this procedure:
1. Connect the power cord, and power on the machine.
2 Remove any paper from the Auto Sheet Feeder and Cassette.
3 Select the paper source with [Feed Switch].
4 Press [Menu] repeatedly until <3.MAINTENANCE> appears.
5 Use [Right cursor ] or [Left cursor ] to sel ect <ROLLER CLEANING>.
6 Press [OK].
The machine starts cleaning the roller.
7 When cleaning has finished, repeat steps 3 to 6 for a total of two times.
8 Load A4- or letter-size plain paper in the Auto Sheet Feeder or Cassette and repeat steps 3 to 5 an
additional three times.

Once you get this done, try to copy 2-3 sheets of blank paper. Let us know what kind of results you get. You should also take a very close look at the position sensor in th ADF to make sure it is detecting the paper in the correct position.

 

[roland6543]

Trigger 37 - a sincere thank you for your advice.

I followed the instructions from step 1 -8, then tried using the ADF and it worked!!!

However, it has intermittently worked in the past, only to become a problem a fw days later, so I wont get too excited yet.

I just want to clarify a few points from your post that i may not be understanding properly:
1) The steps 1-8 seem to be related to cleaning the roller from the cassette/sheet feeder, and have nothing to do with the ADF - right?
2) By opening the ADF, I was trying to go beyond what is provided in the user guide and get to see if anything was faulty inside the adf itself.
3) I'm not 100% sure which part is the position sensor of the adf. What I do know is that when the problem occurs, the grey/black part inside the adf lid is lying flat in a "down" position. When its working OK, that part is in a "raised" position.

Sorry, if my descriptions arent clear. If you wish I can try to take pictures and show you what I mean.

 

[dkossman]

Hi guys, I also have an ADF problem with my MP780 - I love the machine, but the ADF stopped working. if i put more than 1 page into the ADF, it sucks them all in at the same time. Any idea how to fix this? I tried Canon support, (who offered me a discount on a new machine), and I tried the "roller cleaning" procedure above, but the problem remains. Obviously i opened the ADF to take a look but i don't quite understand how the mechanism that is supposed to pull just the bottom page is supposed to work...

thanks for any pointers...
- Don

 

[roland6543]

Final update:

About 1 week later and all is working fine. If only I had known the fix was so simple.

Thanks for all the help.