Possibility of Upgrading/Repairing Toshiba Qosmio F45 Laptop

I have a Toshiba Qosmio F45 that had it’s graphics card fail around 12 years ago, I kept the laptop in question and I am now wondering if the graphics card could be replaced. Now I know that it is impossible to replace parts like this on a laptop due to them being fused to the motherboard but I was wondering if it would possible to say replace the motherboard with more updated hardware of similar type or of the same make. It is a good laptop and much better designed than most modern laptops so I thought it would be a good idea to see if it could be repaired at least as a backup.