Replaced MOBO. Now have 2 problems. First, nothing comes up on monitor. When I replaced MOBO there was a single black wire, or cable, that I couldn't find where to plug onto new MOBO. Second, once I powered up, all the lights work and fan is running but the power button will not turn laptop off. Have to unplug charger and remove battery. When I put battery back in and plug charger back in I can power up using power button. Please help.