Why is my canon mx420 pixma not responding to print?

Here are a few things to do:

1. Check to make all cords are connected, and the power is on.
2. Go online and find/install drivers for the Canon Pixma MP470. A simple google search will find it. Be sure to download the correct version-- whether it's 32 bit (x86) or 64 bit (x64)
3. Go to your computer's control panel, then click "Hardware and Sound", then "printer" to make sure it's being recognized by your computer. If it is, make sure that it's set as the default printer.

Without any more information, that's all the advice I can give you.