Phone [Q] Power button not working!

Hello members of XDA Developers!
Okay so I`ve had my Galaxy Ace for less than a year.
Now I have a problem. The power button one day suddenly stopped working. I don`t know if it`s caused by costom rom which I installed some months ago. I haven`t dropped my phone or anything, but maybe some water got in there.
Now as the phone is turned off, I can`t turn it on. When I connect it to a charger it shows the charging screen.
What should I do. Is it possible to fix? Or is it at lest possible to turn the phone on using computer? I`m planning to give it to service centre so they can (I don`t know if actually can) fix it.