[Q] Phone refuses to boot - sometimes.

I've run into a problem with my S4. I'm rooted, and running Hyperdrive 15.

My phone refuses to boot quite often. Sometimes it will boot up perfectly fine and run for a day - day and a half, or it'll lockup and then refuse to boot up again, OR it will just not boot at all. My power button seems to be unresponsive, and the only way that I can get some action out of the phone is by reseating the battery in the well.

What I think it is, could be 1 of a few things, or a combination of them - i'm not sure.

Scenario 1: While playing with the Hyperdrive tweaks, my phone was hung after running the Zipalign tool for over 20 minutes and I had to pull the battery.

Scenario 2: I'm deployed on a ship currently, and I have my phone in a high-salt enviornment and I'm afraid that there might be salt corrosion inside of the power switch or the USB connection - shorting it out. I took my phone apart tonight and cleaned both items with isopropyl alcohol ( the switch itself on the main board ) but that didn't seem to produce any new results.

Scenario 3: I was recently rooting a Kindle Fire HD 7" for a friend out here, and I was dumb and didn't realize that I was pushing boot loader files that were designed for the Kindle Fire and not for my Galaxy S4. I have since tried to enter recovery, but with little avail. Download mode is also out.

A description of what my phone does when I reseat the battery: My phone will vibrate, the Galaxy S4 logo will show for 1.5 to 2 seconds ( same for download mode ) and if I hold the appropriate button, ' Recovery Booting.... ' will display as well. At that point, my phone will shutoff and the power button will become unresponsive.

If anyone can give me a bit of guidance on how to proceed to repairing my phone, I'd be super grateful.

Lennyz1988, thanks for the quick reply. Internet out here is slow at best, and sometimes unusable.

As far as your JTAG option, I believe that would work, except that I dont have access to that kind of hardware right now. Sending my phone out at this point entails a month of transit time on each side of the turnaround time required for someone to re-flash my phone, and I wholly believe that I can do this.

As an update to my phone, it will not charge the battery anymore. I'll use someone elses phone to charge my battery soon. If anyone can give me a direction to go as far as how to completely reflash my phone IF it turns on, i'd be grateful beyond belief. I dont want to believe that if I can get it to start up again, that it is a total brick and completely useless - if it turns on again, i need someway to push new boot loader files to it. Really hoping someone can help.

Thanks again in advance.