Light blinks -will not stay on - door will open but to close I have to use a key to pust to butten in HARD - but on new button - same - friend said to look at the four wires -- do you have a picture of how the four should be connected?

I can't locate a wiring diagram. But have you changed any of the original wiring since the time the door operated properly?
Since it will open but not close, sounds like a problem in the sensors that prevent the door from closing when an obstruction is sensed.
When you press that button so hard with a key and it works, that just makes no sense to me.
Maybe this generic switch instruction will help:
How to Replace Wall Switch to a Garage Door Opener | Home Guides | SF Gate (http://homeguides.sfgate.com/replace-wall-switch-garage-door-opener-53104.html)