System Freezes

[rastafari514]

Long to explain , going to make it short ... tried installing Ubuntu , system kept freezing up , replaced power supply , memory chip , hard disk , tested ram turned out ok , hard disk check turned out ok , Ubuntu installs fine , get the login prompt and then the system freezes , replaced mouse and keyboard , still the same problem , could there be a problem with the motherboard ?? Stuck and in need of a solution

Thanks