"Traces of love... long ago... that didn't work out right"... lol (sorry, love that tune)
Did the old battery eat away at some of the circuitry? Pretty common and check to be sure the components are still good - diodes and resistors especially. Did you just replace it with a coin-type battery kit? I did on my A3000 and even after resetting the RAM and repairing the traces, machine exhibits the same problem as yours
