Abstract: A display circuit board is provided for a heat dissipation system. The heat dissipation system includes a fan tray, a control circuit board, a plurality of fans, and a display circuit board. The display circuit board includes a plurality of light emitting diodes (LEDs), a thermal sensor, and a connector. After the thermal sensor detects the temperature around the heat dissipation system and transmits a temperature signal to the control circuit board through a signal transmitting cable, the control circuit board adjusts the rotation speeds of the plurality of fans according to the temperature signal, and further transmits a plurality of display signals, which indicate the operation situation of the plurality of fans to the corresponding LEDs through the signal transmitting cable.