I have a Gateway GM5478. It started going to sleep every time it was on. The last time I had it on I was watching a video. All at once it went off and the monitor said entering power save mode. Now it will not come on at all . When I pushn the power button, the fan will come on for about a second. The power button light is also on , but that is the onle life it has. Could this be a bad motherboard?