[win7] T400 doesn't start up on battery

[Mighty_Mauz]

Since yesterday my T400 doesn't start up anymore when it is on battery. The windows 7 startup animation freezes and the pc doesn't respond to anything anymore. Rebooting gives the option for start up repair, but that also freezes. Even booting from the windows 7 cdrom freezes. And every time it is at the exact same moment, so it doesn’t look like an overheating problem. The weird thing is that there are no problems or what so ever when booting with the power cable connected. And after booting, taking out the cable is also no problem, I can work for hours on battery just as normal, but not rebooting.


I have no idea how to fix this, any suggestions?

[Mighty_Mauz]

All of a sudden a week later it just works again, without doing anything other than just using the pc normally. Strange...

[Mighty_Mauz]

Actually the problem has never gone away. And also now, after installing a new hdd and reinstalling the system, the problem is still there. The startup of Windows 7 freezes with the logo animation, everytime exactly at the same moment. (although at 0.5 seconds earlier than before the reinstall and hdd replacement)

What do you guys think? A memory problem?

[GomJabbar]

I had a similar problem with a ThinkPad 600E running Windows 2000. Most of the time it would not boot with the battery installed, but sometimes it would. Turns out the battery was bad and the bad battery even burned up the charging circuit on the motherboard. I had just bought the used 600E from a local computer shop, and exchanged it for another unit. First though, they gave me a different battery to try. IIRC, the motherboard in that first 600E damaged that battery as well.