Hi, I'm an usual reader of MacRumor's forums and it's the first time I'm posting here, thank you all in advance for sharing your experiences. I've just bought a second hand MacBook Pro 2014 two days ago, and until now it had been working perfectly. Today I bought a very cheap powered USB 3.0 hub and connected to the MacBook while the computer was off. The hub itself was on and with a HD connected to it, and the MacBook was connected to the MagSafe charger. When I pressed the power button nothing happened, no chime, no video, no burning smell, no sound, nothing. I disconnected the hub and MagSafe and it won't turn on. Since then I've tried pretty much everything I could find on the web: disconnecting the battery, pressing the power button for ten seconds, SMC reset, and some other things. The fan spins, sometimes it spins and stops, sometimes it goes on and nothing else happens. Is it possible that the Hub fried my logic board? What would be the possibilities? The MagSafe wasn't connected do a surge limiter, could that be it? Could the guy have sold me a MacBook with some non apparent problem? I ran apple diagnostics when I got it and it was fine. Now I know I was way too negligent with the electrical part, but it's my first mac and I'd be very sorry if I broke it so soon. Thank you!