What happens to a motherboard with extra Watt

Hello,
I am looking for a suitable answer.
I bought a power supply unknowingly which was 500W but my mother board could only accept 145W.
Now my question is what happened when i connected those two.
It doesnt start up or do any thing is my mother board fried or would replacing my powersupply do the work.
All it shows with the 500W one is it starts up for 1 sec and turns off
it shows nothing else and its fans rotate for 1 sec too then it shuts down this happens repeatedly after 3 sec interval.
Thank you