I just recently purchased a jetway p4 motherboard.
When i put the 20 pin and 4 pin connectors, the motherboard starts to make a buzzing sound and will not switch on.

When i put the 20 pin and 4 pin connectors

Are you referring to the power connectors here?

Are you sure you have got the board mounted in the case right? You need to use nuts or lugs of some type to stop the board shorting on the case. They are always supplied with the case.

Are you sure the power supply is functioning correctly? Have you tried shorting out pins 14 & 15 using some needle nosed pliers? This will turn on the power supply.

If these checks are done and the problem still isnt solved then I would take the board back. Personally I would have done that already, before even posting here.