I had the same problem with my Toshiba Satellite A75. I just got it out of the shop last week. Of course my warranty had expired, but I stilled called Toshiba. They extended my warranty and covered the repair cost.
I had to take the laptop into an authorized toshiba repair center. You can find the one nearest you on toshiba's website.
This is a well known problem with the Toshiba Satellite A75, and it is listed on toshiba's website as being a problem that will be repaired at no cost to the owner. However, you may have to inform the repair center of this. If they are still unsure, then you will have to contact toshiba so they can fax an authorization to the repair center.
I was told by the repair center that there is a short somewhere in the system, and they had to order a replacement part. I was without my laptop for about 9 days.
Hope this helps you.
My toshiba satellite a75 laptop turns off immediately after I turn it on. Before that I was getting all kinds of stop error messages. I formatted my hard drive, but was unsuccesful installing Windows XP. It turned off automatically after it got to a some point. When I turned it back again, the screen was black, and the fan got quiter as well. Now it has gotten even worse. It turns off right after i turn it on. I know for sure it has nothing to do with power supply. I am guessing it is the processor or the CPU cooling fan. If you guys have any idea please help me out here. Thanx.