20 Most Recent Canon PIXMA MP780 All-In-One InkJet Printer - Page 6 Questions & Answers

Service error 5C00 is a purge unit error. The purge unit like a spitoon to the printhead where is stops. There is a sensor in the purge unit; when it is blocked (usually by ink build up), that error is given. The error indicates that the purge unit may be full or at least gunked up. It may be possible to clean the purge unit and sensor to make the error go away. I base this on information learned with experience on another Canon product (Model i560). Hope this helps...

Sounds like you are faxing multiple pages through the document feeder and it is trying to grab a few sheets instead of just one.
If you are doing multiple pages make sure they are aligned and separated.
Maybe fan the pages and then pat them on a level surface to make sure they are aligned.

Auser manual can be found here: http://www.usa.canon.com/cusa/support/consumer/printers_multifunction/pixma_mp_series/pixma_mp780#ServiceAndSupport

This may help: http://www.usa.canon.com/cusa/support/consumer/printers_multifunction/pixma_mp_series/pixma_mp780#BrochuresAndManuals

Inkjet printers need to be used frequently to prevent ink drying out and blocking the print head nozzles. If the print head cleaning maintenance routine does not clear the blockages, then print head needs replacing, but it may be expensive. It may be more cost effective to buy a later model and better printer than replace the print head.

The larger of the two black cartridges is used for text only printing.

The saller cartridge is used for black in graphic images or pictures.

This saves you color ink . It allows you to put the black ink on the image without making the color inks blend the black ink.

Don

When the printhead goes bad that sometimes happens. If the carriage is not locked on the right, you take out the inks and the printhead and see if it powers up. If it does, you need a new printhead, the part number is stamped on the side.