SNIP
I think that means something related to video, is
blocking the states. The system states supported is in
pretty poor shape, as it's missing S3 and S4.

A couple Googles show people are trying to re-install
their video driver. You might take a look in Device
Manager (devmgmt.msc) first, and see whether everything
is clean and there are no yellow marks and so on.

Hi Paul,

There is a yellow (Device Manager) for "Other devices", "Video
Controller". The "Device Status": "The drivers for this device are not
installed (Code 28). This T23 laptop was given to me years ago. I will see
if I have the driver for this and give that a try.

I will let you (et al) know the results after (if) I find the video
driver.

Hi Paul,

UPDATE:

I found the display driver and installed it.

By golly, I now have "Standby" !!!

Many Thanks for your help, John