Pc not starting switch board No 2

My self krishna.. Am using wipro desktop with windows 7. Problem -pc No 1 is working perfectly in one place with switch board No1 and not working in another place with switch board No 2 resulting repeated restarts. But pc No2 is working with switch bd 2. I tried by inter changing each and every cable, montor and ups also. What is the technical problem i cant findout.please help me out of this problem.