Decode the beep code. If not, double-check all jumpers. Push down on all chips that have sockets in attempt to reseat them. Be sure the core voltage is correct. Be sure the CMOS battery jumper is in the correct position.
Some distributors purposely ship motherboards with the jumper in the wrong position.
If you apply power to the motherboard with the jumper in the clear position you may damage the motherboard. Pull all boards except video. Check the monitor plug for bent or pushed-in pins, connect the monitor and nothing else. Check the monitor power cable. Check the CPU for bent pins.