I cant find a reference in the user guide for the indicator light on the front of my TC1100 tablet, or how to control it. I landscape mode it is the light on the far right and seems to indicate infra red action or sound maybe. Could some kind soul tell me how to turn it off and what it is for.

You first need to Dry-Boot your tablet, it will drain any static/volatile memory/elictricity that maybe preventing your tablet from properly turning back on.
Disconnect the keyboard, disconnect the power ac adaptor cable (power cord), remove the battery and also remove any USB or PCMCIA devices that are plugged into the tablet (if any). Now go ahead and pull the power button except pull it and hold it pulled (kinda lilke when you turn the tablet on, except don't release the buttton) for at least 2 minutes. Two minutes later let the power button go and plug the AC Adaptor cable in (power cable), first check the Power Indicator light on the front of the tablet, if it lights up, then your tablet may possibly start-up. Once the tablet started, go ahead and plug everything back in. Also be sure to check if the battery is charged (on the back of the battery there is a button you can press to check what the charge approximately is or you can check it from Control Panel or System Tray once the tablet is up and running).
Good luck!