T400 Bluescreens when on battery (no mains power).

[kiwimeat]

I have a 5 month old T400 (2764-CTO) with P8600, 4GB (2x2GB), 1440x900 LED, 320GB hard disk, Switchable Graphics, 5300 Wireless, Fingerprint & Camera.

It is works flawless when on mains (AC) power. However, as soon as I remove mains power and T400 runs on batteries the bottom half of the screen appears to corrupt (illegaible graphics, horizonal lines, flickering), and then laptop will crash with a blue screen.

The BC error code varies but is usually 1 of 50, 1a, or a. There are a variety of modules reported as faulting but nothing consistent.

The problem occurs regardless of which operating system I try. I have used the Lenovo Vista Business x64 OEM install including Factory Restore, Vista Ultimate x86 & x64, and Windows 7 RC1 (7100). The issue occurs regardless of OS or driver revisions. I have used a number of clean builds and restores without luck.

I have a number of hard disks and the SATA caddy. Swapping drives or bays makes no difference.

The system can be made to be more robust by switching to a lower resolution than native (1440x900) - eg 1280x800. This works better in ATI as Intel will crash sooner or latter even at the lower resolution.

Also I have not experience any BS in Safe Mode (800x600?).

I have tried multiple revisions of the graphics drivers and most other drivers.

I am leaning towards a hardware issue possibly around power but it could be the system board or battery. I have tried creating modified power profiles but this hasn't helped.

Any advice or suggestions before I log a hardware fault would be gratefully received.

Thanks.