ok was playing gt4 this morning and the ps2 was fine. Was just about to play again and my ps2 will not power up

its getting power as the red standby light is on and go's green for about a second then back to red. Im unable to check that all the wires on the chip are connected as i dont have a screwdriver the right size to fit the screws on the metal motherboard plate.
Any help is appreciated
Ashley