B200 Error on Canon:
1. Open printer
2. Remove ink cartridges
3. Un-install printhead
4. Clean back of the printhead (electronic pins) with alcohol (isopropylen cleaning alcohol if possible). Make sure the pins are 100% clear.
Clean the print head nozzles by pouring water from the top and shaking the bottom on a plate of water. Do this, until there is no colors appear in the water.
5. Turn off the printer (do not close it!) by plugging-off power cord (do not use power button).
6. Clean electronic pins in printer (the pleace where you install printhead). Make sure its 100% clean.
7. RE install printhead, then install ink cartridges.
8. Plug in power cord.
9 Turn printer ON normaly.
When the print head moves half the way to the left, close the printer lid.
10. Check if printer is working normaly (no errors).
You may have to try the head cleaning many times. For me it worked on second attempt. After cleaning and wiping, I blew some air into the print head nozzles to dry them off and clear any particles present.
If error B200 remains = your printhead is damaged = (sorry to say) buy new printer.