You need motherboard speaker for next operation
Reset BIOS-take out motherboard battery for 5 sec and return it back and reinstall CPU ,and check that CPU power cord is connected to your motherboard.
1.Leave only PSU+CPU+motherboard(disconnect all another things) and start PC
2.If you have long continues beeps-move to the next step .If you have no beeps-CPU or MoBo is faulty
3.Insert one RAM module and start PC. If you have 3 long and 1 short beeps continue to the next step. If you have no beeps or still have long continues beeps- MoBo or RAM module is faulty.You must to try all RAM modules and all RAM slots.
4.Install GPU and start PC if you still have beeps-GPU or PCIe slot is faulty