Abstract: A display panel assembly for displaying and monitoring computer states and states of the fan of the computer; the display panel assembly having an area which is twice of a 5¼ (five and one over four) receiving groove of a computer display panel. The display panel assembly comprises a machine case. The machine casing comprises a cartridge seat; a circuit substrate; a button panel; and a mask plate. In assembly, the mask plate covers upon the button panel so that the button holes are aligned to the buttons on the button sets. Then the mask plate covers upon the cartridge seat; then a plurality of screws passes through the through holes and the via holes of the vertical folding sheets, and the via holes of the circuit substrate so as to lock the cartridge seat, circuit substrate, button panel and mask plate together.