Answer to "Power button not working"There is another thread that carries a lot of possible solutions for you. Although it primarily centers around Galaxy Nexus but you might get some useful tips. Check it out: ''Power Button stopped responding. Phone will not turn on.
Answer to "Power Button stopped responding. Phone will not turn on."Phew! Had to sweat it out a lot, and by a lot I mean a LOT! Tried the permutations and combinations of the above-mentioned methods to finally switch on my device. Katzz's method seemingly worked for most of the 'victims' but for me it somehow didn't. Isaya's solution worked for around 60% times. Rest of the times, it was just me doing trial-and-error. But thanks to both of you for providing the fix and helping the people out here in general. My solution: If Katzz's or Isaya's solution didn't work for you and if you have some patience, do some P&C around their solutions. Monkeying around charging, USB, battery placement and continually torturing the Power button worked for me. Not sure how effective would that be for you :) Edit: I forgot to mention that I have a Samsung Galaxy Nexus i9250M.