T60 goes to battery even while AC adapter is plugged in?

[thinkpac]

I have noticed this happen every once in a while (maybe once a month or so). My T60 (which I always have plugged into the AC adapter) will go to battery for a few seconds for some unknown reason, and then goes back to AC power. I can tell it goes to battery because the screen goes black for a split second, and then I see the battery icon in the system tray. But it's only running off the battery for a few seconds, and then it goes back to AC power. Weird. I wasn't even doing anything when I noticed it happen a few minutes ago - I was working on my desktop computer next to the T60 when I saw the T60 screen flicker. Probably not a serious issue since it only happens once every 1-2 months, but wondering if anyone else has seen something like this?

[Harryc]

The problem is so random it may be difficult to pinpoint. In order of things I'd try if it were my T60...see if you can repeat the problem by gently wiggling the power plug at the back of the laptop. Try another circuit in the office/house. Try another AC adapter. Try another battery. As an experiment you could remove the battery and see if it simply powers down now, but make sure you are not doing anything with important data during this test.