Microsoft Lumia 640 XL LCD backlight is not working after water damage

After water damage, My LCD backlight is not working, rest of the functions are fine. Touch glass and touch screen as well. I went to the service centre and they told me my motherboard is screwed up but i dont want to buy it as rest of the device functions are fine. I can feel the navigation keys vibrating, notification sounds and keypad sounds. The only thing is, the connector(i dont know what its called) on the motherboard which connects my LCD light is burned/messed up. They said its waste of time to repair. Any help ?