oh and the problem is the system is not getting started even when i have assembled everything. power is checked and the system does turns on i think becoz i see processor heatin up and fan working but i dont see anything on screen. its an LCD screen so it automatically turns on. but its not now. trust me theres nothing wrong with lcd. and theres 2 cables that goes from powersupply to motherboard. one is 4 pin and one is 15 pin. i doubt the 4 pin might be broken. but not sure.. help me plzz