graphics processor issue on MLB

[jcliles2]

I had a repair done to my mac because it was beeping when i tried to turn it on and the display stayed black. They only replaced one part... does anyone know what this part actually is and what it would have cost me to buy myself???

it says logic board: Item number 605-1795

I cant find out what this part even is...

 

[Sun Baked]

MacBook Pro 15" (Model A1260) 2.4 GHz Logic Board = $700 + Install