Vita 2000 Won't Power On.

So, I recently got a Vita from Japan where the seller did say it was getting power but not turning on. When I got it that was the indeed the case. When plugged in to charge a solid orange light would come on, but it would not start up. No other lights come on. Things I have tried:

-Charging it for 15 hours (orange light never shut off)

-Holding the power button for up to 2 minutes

-Holding power+R-shoulder+PS button for 30 seconds

-Unplugging and re-plugging the battery

-Unplugging the battery, holding Power for 15 seconds re-plugging the battery

-Swapping for a new battery and repeating above steps

The only thing that has changed with the new battery is that the orange light does shut off after charging. So I figured the original battery was indeed dead and not taking a charge. The new one is clearly taking a charge, but it still won't turn on. Everything inside looks brand new too. No corrosion, nothing.

The only other thing I've been able to find is one person saying the charging regulator behind the USB port on their 2000 model got extremely hot and drained the battery, rendering the whole pcb useless. And that replacing it fixed the problem, however since my new battery is holding charge I don't think this is the issue and I'm at a loss as to what the issue could be at this point.

Any insight or suggestions would be great, Thanks.