DC In Board Defective - charge symbol flickers?

My wife's iBook problem began with the screen shutting off while plugged in to the AC adapter. Tried different adapters and isolated the battery as dead and not holding charge. New battery works fine but now I notice what may have helped kill the first battery. When different AC adapters are plugged in to verify it's not the adapter, we sometimes see the charging/battery symbol randomly flicker from one to the other and the screen seems to very slightly dim in synch. with the symbol change. If I gently move the AC male adapter while plugged into the female plug in the iBook I can make the flickering stop. Since this occurs with any AC adapter I've tried I believe my next step would be to replace the DC-in board. Does this make sense as the next step or have I missed something I should test first? Thank you/Curtis