System will not boot after power outage

Power outage is common thing where I come from , initially it would turn on nice after every power outage , then once power went off and it wount power on , I tried everything .

I opened system, when power cord was plugged in , I would see light #1 was on , and the light #2 would start blinking when I push the power button , there was no diagnostic info about that .

I kept on trying plug in plug out and suddenly it started , since then I bought APC UPS thinking it doesnot start because sudden power outage , but even if I shut it down but if the stand by power stops from UPS or direct supply it will go on that i will not boot up mode then again I will have to keep trying SMC , plug out wait 15 seconds then plug in then wait 5 seconds and power on , after 40 to 50 attempts it will power on .

bottom line it needs stand by power all the time , when its shut off . other wise it will not boot up for 1 or 2 days will take numerous attempts then it gets started .

I have changed the RAM , no effect , I thought pram battery must be dead but time and date are working fine without internet connection .

If you have any idea what could be possibly wrong with it , please advise .