Hi, i just finished building a pc and theres no signal. I have a MSI P45 Neo-F LGA 775 mobo, Sapphire Radeon HD 4850x2 gpu and a Corsair TX 750W PSU. The problem first was three red lights on the GPU, which was caused because I forgot to connect the powersupply to the GPU. Now the gpu shows a green light but still no signal. Thanks in advance.