I can't my Alcatel One Touch Idol 3 on. Pleez halp.

My phones power button simply has not been working consistently. I've been getting by though by plugging it in and turning it on whenever I need to get into my phone (which is very often). It ran out of battery and was dead. I plugged it in and it showed to logo and what not but seeing as I am not able to hold the power button down to turn the phone on I am stuck. I have researched for hours on it and I'm getting really frusterating. Finally I was messing around with the power and volume buttons that I might have put it into "downloading mode" whatever that is.

I've tried holding the power button and the volume button on. I've tried to get through on the computer and turn it on but even that wont work for me. If anyone has any suggestions other than taking it in, that would be great.