Chosen Solution
When I plug it in to a 2.1 amp charger, nothing happens, but the Anker IQ charger makes the screen flash and not boot. Is my battery dead?
(idk much about Samsung tablets, but i know what the problem could be as some Nintendo DS models do this and i had a ipad do this) i think the tablet could be doing a “self check”, and something may be wrong with a connection or damage to the inside components making the Samsung not want to turn on and keep you on this reboot cycle. It is possible that it could be a battery issue, but please take my guess with a hint of salt as i have very little experience with Samsung tablets.
80stechkid yes, it could be your battery. Go ahead and replace that first Samsung Galaxy Tab 3 7.0 Battery Replacement If after that, you still have issues with it, I suggest you follow Samsungs flowcharts for the fault finding.
Here is the board layout as to where to find the components to measure.
