Chosen Solution

I was changing the cartridges on my Canon MG5550. I left the machine for twenty minutes with the print head carrier in the access position. When I returned the display showed fault code B200. Prior to me removing the ink cartridges, the machine was working well.

@muppet try this first:

  1. Turn OFF Power
  2. Open the print head bay (as though you were about to change inks)
  3. Turn ON power
  4. Wait for print carriage to start moving to the left and let it go past half way
  5. Before print carriage reaches left hand side (but after going halfway across) shut the cover.
  6. Leave the Printer turned on if that does not work try the suggestions on here.