well i might've screwed up now, try downgrading from 4.3 to 4.1.2 using this method i found;
So I did this a couple times now first by accident, then on purpose. If you want to go back to 4.1.2 from 4.3 all you have to do is use Odin. Flash stock 4.1.2 onto 4.3 you get an error "unsupported firmware" then put your phone back into download mode (volume down+home button+power) next flash CF-auto root. After that you can boot into recovery (volume up+home+power) in recovery format everything factory reset, format cache. Last reboot your phone it should reboot into 4.1.2 I think that is how I did it if I remember all the steps right. Feel free to ask questions I don't always explain myself very well.
i was thinking that this might work because my phone was fine on 4.1.2 so why not try. now on the download screen it says void:1, to make matters worst, it still doing the same thing. bad motherboard?