First of all, I know this is a rehash, but I have found no threads that apparently work. all look very old also.
My Mini 9 is very old. Runs fine.
Replaced the battery (aftermarket), I get the "battery not recognized" flag at boot, and now alternating blinking power and battery lights.
I've tried most of the simple fixes to no avail. (swapping batteries after up, slipping in and out, turning Airplane mode on and off, etc). BIOS retrograde appears, according to this forum, not to work either.
Simply, is there a tried and true fix?
Thanks in advance.