i searched the forum and only can find the solution for N100 series.
My Y400 just 13month old and now have the charging problem. When powered on, most of the time the charging will stop after a while and the power (blue) and battery(amber) LED light is blinking. It will use only the battery power ignoring the AC in until it drain out. If I tried to unplug and plug in the power, sometime it help but mostly not. If I shut down the computer while the LED blinking, it is not charging too. But if I unplug the power first so the light not blinking, then shut down the windows and plug in the power again, the battery is start charging.
I tried remove the battery and use only AC, it is OK.
May I know what's the problem? I am from Malaysia. The local Lenovo help center suggested me to buy a new battery as my 12month warranty already expired. Does the 18month extended warranty for battery applicable for the Y400 series?