Why won't my phone turn on?

[Windows Central Question]

I received the Nokia Lumia 925 last week. It is now at least third hand - my father found it on a work site, broken, and my brother dried it out, fixed it and used it for a few months before upgrading. He had no issues. I then took on this phone. This means I have no idea how old it is, or if it had any problems previous to it being broken and left.
I had no issues at all up until today, when I tried to use my phone in the morning, but found it had switched itself off. Obviously weird because they switch themselves on when charging.
Tried turning it on, but nothing happened, and for the last 4 hours or so, the phone has been 'charging' but still unable to turn on.
The windows icon changes between flashing on and off, pulsing (stays on, but flashes brighter) and being off, and sometimes doesn't flash or pulse at regular intervals.
The charger I'm using is different to the one I used back home, and is a bit dodgy. However, I assume it flashing means it is charging, which
is what it has been for most of the time it has been plugged in.
Soft and hard resets don't work (though I'd rather not hard reset it as I can't get the photos off there).
Could it be the charger? Or another problem that I can't fix myself?

 

[ven07]

Happened to me as well If you want you could download the Lumia Recovery Tool and try that, but mi thinks the phone is dead. I replaced my battery, because I thought that was the problem, but it wasn't. I'm going to replace the motherboard next; it's my 2015 project lol. I'm going to replace it, because I've read that some people who sent in their phones to Nokia were told that a new motherboard was added..

 

[MDK22]

I received the Nokia Lumia 925 last week. It is now at least third hand - my father found it on a work site, broken, and my brother dried it out, fixed it and used it for a few months before upgrading. He had no issues. I then took on this phone. This means I have no idea how old it is, or if it had any problems previous to it being broken and left.
I had no issues at all up until today, when I tried to use my phone in the morning, but found it had switched itself off. Obviously weird because they switch themselves on when charging.
Tried turning it on, but nothing happened, and for the last 4 hours or so, the phone has been 'charging' but still unable to turn on.
The windows icon changes between flashing on and off, pulsing (stays on, but flashes brighter) and being off, and sometimes doesn't flash or pulse at regular intervals.
The charger I'm using is different to the one I used back home, and is a bit dodgy. However, I assume it flashing means it is charging, which
is what it has been for most of the time it has been plugged in.
Soft and hard resets don't work (though I'd rather not hard reset it as I can't get the photos off there).
Could it be the charger? Or another problem that I can't fix myself?

The first bolded comment is very telling, just because it worked, doesn't preclude damage, which showed up, NOW.

it could be the charger ... but, a HARD RESET might be your only option (or it's now DEAD).

BTW - you can possibly find out how old it is, by accessing the Microsoft Lumia site for warranty info. If it's less than a year old, it'll show still in warranty (which doesn't really help with your problem, since it's water damaged, just give you a relative age).