this is most obviously PROGRAMMED OBSOLESCENCE!! I wil never buy Canon again, this is what they will get with their strategy. Moreover the firmware is so bad that it does not even remotely report the possible cause of error and what hint to what should be fixed. But now every generation is just worse than the previous one. I had several HP and Canon in the past but they all lasted between 4 and 10 years. I have to unplug it >10min to start it again but same issue after that. But once I start a check print or a head alignment, the process starts but when it is about to load paper the printer turns off (black screen, no led) and I cannot turn it on again. If I try the "trick" given above (start the printer with panel open, close it after a few seconds) I can access the GUI and swiftly move to maintenance menu. I have a MG6650 since 2y and it did exactly the same: was working well and perfectly printed a set of photos for Christmas and now I get a B203 error right after I start the printer. Sounds simple yes but I just followed my gut feeling. You can do a few more maintenance checks if you want to keep your printer in mint condition. Once done it will print a test page and tadaaaaa! it works. And start the process let it finish and follow any instructions it may ask.
Next go to settings/ maintenance settings / auto head allignment.
Now if you try to print anything the error might come again in which u repeat the steps above. Wait a minute or two and you should be back to normal menu. Now turn on the printer wait till the ink head starts moving a bit then just shut the cover back to normal. While the printer is off, open the front cover where the ink is. So to summarize it in short follow these steps and you may be as lucky as I have. I simply could not throw my MG 7540 Pixma just like that. So I just want to post my solution finally after a while of trying some of the solutions on the internet and none worked for me.