Do you have sound?
When blue light on press power on remote.What happens?
Try reset. Unplug tv hold power button on tv for 60 seconds, let tv sit for 10 minuets, then plug in and turn on. What happens?
With replacement of both boards you should atleast have sound.The blu flashing is booting for a tv before it turns on steady.
What was the inital problem you had for you to replace both boards?