z3 wont turn on

[SKY9674]

I was at a party and used my phone for a few minutes 4 hours ago and there was no problem. Battery was 78%. After a while I realized my phone was not turning on. After coming back home I connected it to the wall charger and the light is blinking red. When I hold the start button there is a red light constantly but it won't turn on. Holding volume up and start button also doesn't work and there is no vibration. I tried the yellow reset button near the SIM tray and that didn't work either. My phone had a 16 GB built in memory which was pretty used up (It kept telling me transfer to SD card since memory was above 75%). I was going to buy a microSD card for it but now this happened. Is there something I can do to fix my phone? 

[SKY9674]

So I finally managed to get my phone to the shop where I bought it, they replaced the motherboard and battery and and said that it was a short circuit caused by an unstable electrical outlet. I'm not sure how it short circuited while it was in my hand. And also if this was the case then can someone tell me if it's safer to charge with my laptop instead of my wall charger? Please and thank you.