MF8380Cdw will no longer print black

[ceath]

Over the past weeks the black print has been slowly getting fainter and fainter.  (The faintness is more pronounced on the right side of the page than on the left.)  Color printing appeared to be OK, although not as vibrant as it once was.

I assumed the problem was that the black toner cartridge was running out of toner, even though the Utility (I'm running Mac OS  10.13.5 High Sierra) said all four toner cartridges are full.  This morning I replaced the black toner cartridge and now the printer will not print black at all.  Printing a test page shows the color part of the image, but no black.  Printing one of my own documents prints the logos and other color text on the page, but none of the black text.

I downloaded the latest drivers from the Canon web page and reinstalled the printer drivers.  That did not change anything.

Any ideas?  Is it time to purchase a replacement for the Canon?

[ceath]

One other bit of information that probably has no bearing on this, but just in case ...

I open the Mac Printers & Scanners system settings, then open the Opens & Supplies Panel.

The Supply Levels are reported as having four full toner cartridges. I know the black cartridge should be full because I just replaced it. I doubt that the other three are actually full -- they've been in use for a while. It seems to me this may be reporting faulty information.

I get the same information when I use the remote UI panel via a browser (http://canon0e353f.local/portal_top.html).

Even more concerning, when I click on the Utility tab in the Printers & Scanners --> Options & Supplies window, I can click the Open Printer Utility button. That button opens the Canon MF Printer Utility (I can see it in the Mac's Doc and as the software that is running), but I get a message, "The communication method has been switched to bidirectional." When I click the OK button, the Utility software simply shuts down with no opportunity to use it.

So even the rudimentary troubleshooting tools seem to not be able to help diagnose this problem.

[James_C]

Hi ceath 

I recommend cleaning the Fixing Unit to resolve the issue.  If the issue continues, take out the toner and rock it 5 or 6 times to evenly distribute the toner.  Re-install the toner then attempt a print job.

If you continue to have difficulties, please contact our support group using the following link:

http://Canon.us/ContactLI

[ceath]

Thanks for the advice, James.  However, I've tried those approaches:

1. Prior to replacing the black toner cartridge, I had cleaned the fixing unit (Menu --> Adjustment/Maintenance --> Clean Fixing Unit --> Start).  it didn't seem to help.
2. I had also cleaned the ITB (Menu --> Adjustment/Maintenance --> Clean ITB --> Start).  There was no change as a result of doing this.
3. I had also taken the black toner cartridge out and rocked it multiple times to attempt to distribute the toner through the cartridge more evenly.  This actually did show a modest improvement.
4. I also increased the print density, which helped a bit.

After replacing the black toner cartridge (based on my assumption that, even though the Printer Utility says I had a full cartridge, that information was erroneous and that the cartridge was actually spent), I got zero black print (although I did get some color printing as noted earlier).

I've just completed a repeat clean of the Fixing Unit (and, while I was at it, I cleaned the ITB as well).  The Clean Fixing Unit process produced a page with good, solid black diagonal stripes -- so the black CAN print.

Yet when I print a regular text document that is just black text, I get nothing.

When I print a test page using the Canon MF Printer app (Printer --> Print Test Page), I get three symbols in the middle of the page:  1) a letter C with the words Unix Printing System enclosed (in poor-quality black), 2) a circle with the colors of the rainbow that looks pretty good, and 3) a gradiations of black stripe that also looks fairly muddy.

I did try turning the printer off for several minutes and then restarting it.  That did not seem to make any difference.

Here I think may be the most important clue of all:

1. I tried printing the color test page at http://printertestpage.org.  That produced a full page of graphics with color and apparent black, but the image quality is poor.  There is black on the page, but it is muddy looking with a greenish cast in some places.
2. I also printed the black and white test page at http://printertestpage.org.  That produced nothing -- no print at all.

So is the problem related to the printer being unable to handle true black print, but it can produce black, after a fashion, by combining CMY ink to resemble black?

Thanks for your help on this.

[ceath]

Does anyone have ideas for what would prevent a laser printer from printing black (even after the black toner cartridge has been replaced), even though the printer can print colors fine (even approximating black by adding the CYM colors together) and even though the Clean Fixing Unit process produces a page with good dark black stripes on it?

My assumption is that the problem has less to do with the black toner and more to do with the way the printer is processing black images.

I've got a printer that is useless because it can't print black text.

[ceath]

Today I received a response from Canon (copied below).  What gives?

Apparently Canon wants me to mark their reply as having solved my problem.  Does no one read any more?  Or is it only robots that work at Canon?

This respose is, it seems to me, an automated response to just clear the forums so Canon can check off another request completed.  But it does nothing to solve my problem, which has been described in some detail.

Time to find a new printer.

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[James_C]

Hi Ceath

Based on the described issue and the steps already performed, it is recommended at this point that you contact one of Canon's Technical Support Representatives. To contact a Technical Support Representative, please use the link below:

http://Canon.us/ContactLI

[ceath]

I am closing this ticket.  No useful suggestions here in the CanonCommunity.  

Contacting Technical Support provided basically the same information with the suggestion that I take it in for repair.  Since the repair will cost more than replacing the printer, I'm scraping a very nice printer that has apparently one fatal flaw.

[James_C]

Hi ceath,

I recommend cleaning the Fixing Unit to resolve the issue.  Please click HERE for instructions to clean the Fixing Unit. 

If the issue continues, take out the toner and rock it 5 or 6 times to evenly distribute the toner.  Reinsert the toner then attempt a print job.

If you continue to have difficulties, please contact our support group using the following link:

http://Canon.us/ContactLI