Screen will not start - blue light on LG start up flashes on and off about every second? Not the pc backup screen is fine - is it fixable?

Check the monitor on a differant pc or laptop to make sure the problem is the monitor. Unfortunetly unless the monitor is under warrenty it isn;t that cost effective to fix. The price to repair will be as much as a new monitor.
The parts are cheap but the labor isnt. So if you can find some to look at it get an extimate and know what a new one is worth before spending any money.