This can be a complicated issue. The only thing you can do is to:
1.Turn off the printer.
2.Unplug the power chord.
3. Open the front panel.
4. Remove all the ink cartridges
5. Carefully un-install printhead
6. Clean contacts or the electronic pins at the back of the printhead with alcohol (I recommend using 99% rubbing alchohol).
7. Turn off the printer (do not close it!) by plugging-off power cord (do not use power button).
8. Clean electronic pins in printer which is where you install printhead.
9. Re-install the printhead and then the ink cartridges.
10. Plug in power cord.
11. Turn printer ON normaly.
If you still have the error B200 remains there is a huge possibility that your printhead is damaged. At that point, the only thing left for you to do is call canon support.
Happiness for your Printer
