if no power try replacing the power cable,
if it is error B203 try the below link steps,
Sometimes, the Error Code B203 indicates that there is an empty ink cartridge. Now, if your Canon printer is running on two different kinds of ink cartridges. Then, it might possible that one of them is empty and that is creating this error on your system.
[https://www.youtube.com/watch?v=ao9aRyPgbCk|LINK]
or tey doing a hard reset : [https://www.youtube.com/watch?v=JwE2Wy8K3IU|LINK]