I could be wrong, been a while, but if trying to transfer contacts to another phone, it will save through the GMAIL on the phone as long as it was synced with everything. Which would of auto done so if you didn’t do anything with it.
When it comes to fixing it, if you haven’t tested the battery, try getting another one, or a step that may see if its the problem. Take the battery out if possible on that phone, in which I think it is, plug the charger in, and see if it turns on being powered directly just from the charger. Turns on then buy a new battery. If the motherboard is killed, you can't do anything besides replacing it and I’m not sure on replacing a phone motherboard.
But there is this!
Samsung Galaxy S5のマザーボードの交換
An IFIXIT guide on replacing the Galaxy S5 motherboard. The motherboard for the phone can cost about 20-30$ to buy online. Way cheaper than what you’re saying. So they’re is still a chance! Doesn’t seem very hard to do at all tbh.
ALSO! An easy test after the battery (If its not the problem) and to not spend money… you could try resetting the phone and see if that fixes the problem. I’m not sure if that would do anything but you could try.
https://support.bell.ca/Mobility/Smartph...
That guide is very very short and explains how you can reset the phone without turning it on. Goes into a form of safety bios mode in the phone. But you may want to keep your data on the phone in which this isn’t an option for you but if you are just trying to use it then you could try this.
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