Hello:
I just want to say that I solved my Canon B200 error through this thread, and I signed up just to say "Thank you!" I have a Canon MX892 Multi-Printer, only about 18 months old (new cost about $350 now). I ran ink low, and got the error. I worked on all solutions found on the internet for the past week. Finally, I took it in to the repair shop, our local Cartridge World, left it overnight for inspection, and the guy said it was junk. Well, I was going to keep the old printer, since I decided to buy a good used Canon MX892, and then I could use the brand new inks I just bought for $50, and perhaps the print head. I sent my friend back to pick it up, and he came back with the printer and inks, but not the print head, so I sent him back for that, as well. I decided to soak print head one more time overnight in alcohol. This morning, I once again replaced all inks in the printer and the print head, and still B200 error.
Then, I again began searching a little more complex phrases, like "canon power supply," etc, and ended up here. I decided to take out the back plug in unit where the cord goes, as stated here, and just make sure the connections were tight. The plug unit came out without removing any screws--just pushing the top clip, and wiggling up and out from the bottom screw. Inside, no circuitry, but a grouping of blue wires attached to the little white plug, and one loose white wire with a metal end that was secured to the unit so as not to be floppy, but not connected to anything. I just pushed on the white clip with the blue wires (because I was afraid to pull out wires and couldn't get it out by lightly pulling) just to make sure it was seated good, and put the whole unit carefully back in. Then I put the printer back on my desk, plugged it back in, and Voila!, it works again! The printer went through all maintenance operations that I choose to do (cleaning, alignment, bottom plates, rollers), and then actually printed a document! Yay!!!!!!!! I'll keep my fingers crossed, but for now, it's working, thanks to your post! Thank you so much, and I hope by posting this, I can help other people with the dreaded B200 error, when other solutions don't work for them.
Take care, and again, thank you!