Default [Q] dead SCH-i515 / read internal memory

Hello,

I have a dead SCH-i515. I have replaced the usb charger adapter and still no luck. At this point the problem may be the motherboard.

Question is, if I replace the motherboard (and this fixes it) would I be able to read the existing internal memory/simcard module in the new motherboard?

EDIT: the phone does not turn on at all, no fastboot, no detected on the computer, nothing..

Sorry if this is not the right place to ask. I have been looking over the forums and haven't found this question at all.

Thank you for your help