Provided is a socket for testing a main board having a water-cooled cooler fixing structure that fixes a water-cooled cooler to the top surface of a central processing unit mounted to a main board for a computer during testing of the fraction defective of the main board. A bit error rate estimator obtains bit error rate information regarding the bit error rate of the received signal, corresponding to the received data symbols, by evaluating the reliability information. The igniter burns atomized fuel that exits the atomizer and is mixed with preheated air.