no power to motherbord,mouse,keyboard

There's a few things that can be wrong :

1. The power adapter to the mainboard is not properly connected. This might seem strange, but that plug can be seated poorly, so it will still start the machine, but it might not give power to the main board.

2. Remember that your fans and DVD R/W works of different power ports, so even if they are working, it doesn't mean the power supply is not faulty. If the circuits powering the main board are faulty, your other components could still be getting their required power, so if you have a multi-meter, double check your power supply output. Don't do this if you are not sure of what you are doing, please.

3. Check if the RAM, expansion cards (AGP etc.) and CPU are properly seated. Any one of them not sitting properly could prevent the main board from firing up.

4. Check that the CPU fan spins. On some main boards, if the CPU fan does not fire up, the board will shut down immediately to prevent the CPU from burning out.

5. Unplug ALL devices, even your monitor, from the machine an switch it on. Then plug in the monitor and see if there's anything happening.

If none of this works, you might want to consider getting a more experienced person to take a look.

actually when i removed my ram and try to start up. bcoz to test whether the motherboard is functioning or not.. bt motherboard did not made a beep sound.. hat might be it..??