Shortly after opening FB, my screen will go black. FB continues to run, but cannot get screen visibility back. Removed battery, reset, phone goes into reboot loop: shows Samsung Galaxy 5, pauses, goes black, repeat. Remove battery, reinsert, do not turn phone back on for a while, phone will usually restart as normal. Went through this last nite, then while on FB, phone suddenly went to a screen covered with red & yellow jagged lines. Removed battery, left off overnite, and appears to be okay for phone calls. Suggestions?