I have a Toshiba Tecra 9100 laptop and it won't power on at all. The power LED on the front of the laptop is flashing amber. I have removed the battery and also tried a different battery which I know definitely works but nothing happens at all. Any help would be GREATLY appreciated.

I am pretty sure you will find that your motherboard has 'gone'. This happened to me with my Tosh and, after many phone calls and discussions with IT teccies, I have finally decided to buy another laptop - the cost of a new motherboard and labour charges to install it make it pointless sending for repair. Sorry for the bad news.