Problem with system turning itself on
It seems that there is some hardware flaw that affects a small number of users, where the power controller wakes the system from deep power off states including suspend, hibernate, and halt. The people affected by this seem to have had recent Windows XP "downgrades" installed, but this may be coincidental. This problem persists even after verifying all normal situations such as Wake-on-LAN settings being misconfigured.
Symptoms and troubleshooting steps to try:
- Halt from the GRUB boot menu: should power off, but this problem leads it to power off and then restart
- Press power button on BIOS screen: should power off, but this problem leads it to power off and then restart
- Lenovo Windows Vista install may mask this problem somehow
- Try replacing the keyboard to check for possible defect with the power-button (though it appears not stuck, the defective circuitry can trigger the system to randomly turn on by itself).
Getting tech support from Lenovo has been difficult because they'll install Vista and say it is non-reproducible. Insist that they try the BIOS test described above, to rule out operating system interference. Another test is to remove all power sources, press power button repeatedly, and then reapply power. A proper machine remains powered off, whereas ones with this problem power up on their own once power is applied. However, some repair technicians do not seem to recognize this as a problem.
The repair performed under warranty service has been to replace the main system board. This has been verified to solve the problem with the same Fedora install on an X200, i.e. the hard drive was removed before service and reinstalled. The problem went away with no modification to the disk image. Judging from Lenovo user forums, this problem also can affect older laptops such as T61. One speculation is that it is somehow related to the Intel AMT controller, but this is not confirmed by Lenovo.