|Umm While this info applies to another model - it might work for yours; no harm to try?|
Canon Pixma MX700 factory mode:
1) Disconnect the printer's power outlet
2) Press and hold the power button while connecting the power outlet back.
3) While still holding down the power button, press the reset button twice.(red circle with a triangle)
4) Release the power button
The printer takes about 10 seconds to show the number 1 (factory mode)
came from here:
via a google trawl using:
Pixma printer mx310 won't turn on
as the search terms/string.
There are a few other hits around too; but not a lot...
Are you sure the power cord is OK; that there are (presumably mains) volts arriving at the printer end of the power cable?