Just did a normal respring and plugged it into a wall charger now it keeps restarting and won't fully power on. Do I need to restore with DFU mode in itunes? I've held power and home buttons but it doesn't fix it. Any help is appreciated!
Try rebooting with the Volume Up button depressed. This'll start the phone with Mobile Substrate disabled, and you'll be able to launch Cydia to remove whatever tweak is causing the respring loop. (It may take a while if you don't know which one it is )