Trying to repair a IBM ThinkPad 600E. The backlight will turn on and off during boot up (like normal), once it has finished booting up sometimes the backlight will be on, sometimes not. If I put it to sleep and wake it up it will flash and sometimes turn on and work fine. Does this sound like a backlight, CCFL, or the inverter? I have heard with the 600's it tends to be the backlight but to me this seems more like the inverter is cycling, since when its working it seems to work fine.