I've been having an issue with my phone the past few days. Started out it would read "invalid sim, need to reboot" or something along that. Anyways this was after flashing a nightly and I figured, OK, it's a nightly i'll live with it. Eventually my phone just started to power off/reboot all by itself; not real consistent but it was happening more than I would like. Today, the S*&% really hit the fan. I flashed a nightly Wednesday night(i'm not going to say which one, because i'm not sure if it was from the ROM itself or if this was a hardware issue). Anyways, Friday at about noon or so, I open a game to play on my lunch break, I get distracted so I lock my phone to attend to something else. I go back to my phone and it is powered off, now totally unresponsive to anything. I pull battery and try to restart, when I place the battery back in the phone it automatically reboots(WITHOUT ANY BUTTON PRESS) I thought to myself ok this is kind of weird. I try rebooting by using power+vol up...absolutely nothing, it's just a brick. Well, I pull the battery again, hold vol up thinking it will go into recovery...nope, it will boot for a sec or two, just enough to get the blue lettering on the top left of the screen then shuts off again. OK, let's put this b*&*h into download mode and see what happens. it goes into DL mode, all the way to the point of where it says " do not turn target off" then shuts down. I did both of these multiple times, with different batteries as well, plugged in and not. It won't stay on for a computer to recognize it. Someone suggested a stuck power button, I don't think so; it feels the same as it always has.
I was fortunate enough to be able to get another S4 with a busted screen so I switched out motherboards. I have a working phone again...which is all I was worried about. I've flashed quite a few ROMs, I follow procedure to the T when flashing... What do you guys think...hardware issue...user issue...ROM issue? I'm very curious to know because I don't want this happening again, obviously. I would even send the phone out to someone to play with(mind you, the screen doesn't work and the silver bezel is crappy because I just used my original one).