Hitachi axm239uk stereo ?

When you turn the hitachi stereo on, the light on the sub woofer turns from red to green then immediately returns to red in the standby position. The screen on the main console also flicks on momentarily then returns to its's off state.I have tried resetting the stereo but this still hasnt solved the problem. Does anyone know whether one of the components inside has gone and which one it is?