im putting together a pc for a friend useing all my spare parts that iv slowly replaced over time but iv hit a snag.when i turn the pc on the power light lights up blue,the motherboard led lights up and all the fans are spinning etc,yet my moniter doesnt pick up a signal,and my keyboard(saitek eclipse) keeps on flashing over and over.iv checked everything in the pc and carnt find anything wrong or missing etc.it has a external graphics card to.what am i doing wrong? also the case im useing doesnt have a system connectors speaker,so im not sure if theres any beep error codes etc.iv also checked the system connectors and the hd led on the pc case doesnt light up,yet its in the correct way,tried it with 2 different hardrives and still the same problem. pleasssse help thanks in advance