I Need a Genius!!! Craftsman 200.57933 Safety Sensors, RPM Sensor or Logic Card Troubleshooting

Hello,
I have this garage door opener from a couple of years ago (it broke like 2 months after) and just now I decided to fix it.
My garage door opener initially was acting strange.  It would open by itself, sometimes the remote would work and other times it wouldn't.  Even after unplugging (resetting it) it it would sometimes for a while and then stopped working.  The infrared sensors were fine.  The light bulb would flash several times ( I don't remember how many) but I know that I looked it up and everything indicated to a faulty logic board.  I replaced the logic board thinking all my problems would be solved! and when I plugged it in it opened the garage door a little bit, without me pressing anything, then closed again and the light flashed 5 times.  Curiously when I unplugged it and plugged it back in the light still flashes but it doesn't open like it did at first.  When I looked at the safety sensors the sending one lights are completely off, the receiving one has a green light flashing.  I realigned them, checked the wire connection to the unit and it is fine.  Also I checked the wall switch (opener) and it seems fine, it shows a steady light; however, it wold not open when pressed.  I pressed it for 2 seconds to reset and nothing happened.  Now I have questions:
1.  Is there anyway that I can by pass the sensors and wall switch to see if that was the problem.  If I disconnect them will that bypass it or will the unit simply not work?
2.  I read somewhere that when the light flashes 5 times it's the RPM sensor.  Is that the case for my model?
3.  We were suffering from power outages at the time.  Would that have damage all, the logic board, the RPM sensor and the sending sensor?

Now I am about to switch back to the old logic card to see if it is any different.
Technicians here charge a fortune and it would probably cost about the same as a new unit, which I am seriously considering.
If you tackled this question I have to sincerely say thank you so much.  You are awesome!