If the light is flaky you may have the larger issue of wires inside the power cord fraying or being loose, which may lead to either simply no power, or a short that may destroy the PS, the DC board, or the iBook, or even start a fire. Hope for the best and that it simply stops working. I noticed the same symptom on my iBook 600 power supply a few weeks ago. I'm currently on the lookout on my local Craigslist for a cheap replacement. I've seen used iBook PS go for $20 a couple months ago. I've been regretting the decision not to pick that up as a spare at the time.