3 Beeps noboot. New Ram, please help

Hi. my pc makes 3 beeps and the wont boot up or show any display. I removed the rams and replaced them with new ones.  I cleaned the ram slots. I tried 1 ram stick in each slot snd then both together. It still beeps 3 times. I unplugged it all and removed the cmos battery, no difference. I tried out of desperation using a different monitor snd keyboard, no difference. i went on tech helpline and they were unsucesfull. The pc is clean and dust free. The ram sticks work ok in other pc's so its not the ram sticks and not the cleaniness of the slots. Aaarghhh ... can anyone help? The motherboard is a Gigabyte 510, thankyou :)