Answer 1

Hi. This sounds much like a hardware (short) issue. You want to starty off by fully disassembling  the Galaxy Pocken and thoroughly flush its system board with electrobic cleaning spirit and let it properly dry (you can use a hair dryer if you have access to one). The reassemble it and retry installing the battery and observe. If that does not do, then you sadly have have a defect board requiring service.

Comments

Hello

Please try this:

1. Remove the battery
2. Insert into a charger without the battery for 5 seconds.
3. After 5 seconds press and hold the power button for 10 seconds.
4. After 10 seconds insert the battery and let the phone charge for at leat 15 minutes and then try to turn it on. 

If it does not turn on at this stage' Please  Press and hold the Volume Up + Home button + Power button for untill the samsung logo appears then release all buutons at once as soon as you see the logo. 

The method above have to take you to Recovery Mode, If does not' you have to take phone to your local phone repair shop for service but if does please comment the results below for further assistance.