iPhone 4 fails to stay on, or turn on, after many repairs

I had originally water damaged my iPhone 4. I had this happen before and fixed so I attempted to fix this solution myself. I happened to rip off my battery connector during this process.

I had let my phone sit for almost 3 months before picking it up again. I had read threads and watched videos and decided to fix my battery connector. I had a few failed attempts until I finally got it working again. During this process I also had changed my battery.

Next, my iPhone had greyed out wifi, I read threads again and decided to try and clean it with 99% isopropyl alcohol. This did not fix anything, but also did not seem to change anything.

I was happy with myself as I had a working phone again, for almost a month, until now.

My problem is that I was just sitting on my couch texting, when I put my phone down for a minute I noticed the screen go completely yellow toned. I went to grab it and before I touched it, the phone had reset and went to apple logo to boot up. I waited and noticed it took a long time (6 minutes). After turning on, it was fine and working only to turn off again in 15 minutes. The battery percentage was fine as it was at 84%. Now I continue to have the same problem, every now and then I can get it turn on and it will not stay on. Also most times it shuts off it will not turn back on while being plugged in. One more piece of information is that the phone will get hot if I leave plugged in (still wont turn on though).

The thing I tried from reading were when I got it on was to restore it, I did. Did not work.

I can also sometimes unplug, and replug the battery and try until it will eventually turn on, just to die in another 10 minutes or so.

Please help, any information may be useful.