System Not Turning On

In my office there is a celeron 1.7Ghz system.The problem is that when I turn on the system only the motherboard LED starts glowing. The SMPS does not turn on .But the SMPS worked when I disconnected it from the motherboard.So I wanted to know whether it is a motherboard problem.If so, is it a major problem
or a minor problem.




Regards,
PRASHANTH