Start with some Google searches of Toshiba repair stations... Toshiba is not well supported in the repair community.
Shop eBay using the ID's and digits on your existing motherboard... There are lots of them on certain days... running from $72 to $150... A lot of Toshiba laptops are sold on ebay cheaply after they have been ruined by a drop that breaks the screen...
See if Toshiba has a warranty issue.
How could you burn a chip set? You need to know so you do not destroy the next Toshiba system board in the same way.
Just be careful that you have a warranty or a buy from a good tech, as there are so very many that were ruined by a system board password that cannot be recalled.