Sound no picture after main board replaced

My Sony TV XBR-65X800G all of a sudden stopped working. The TV wouldn’t come on just red flashing lights. Was told to replace the main board. I replaced the main board and now when I turn it on I can here the set up music but don’t have an image/picture. I can tell it is on because I can see light but doesn’t produce image. There is a solid white light not red anymore. Any advice please ?