I am working on a Toshiba T4600/200 series laptop. The specific model is PA1202U. When I try to turn it on, nothing happens other than "P30" appears on the LED above the keyboard. The screen remains completely blank and I can not hear any hard drive activity. This happens when I am running off the battery and when I have it plugged in. I went to the Toshiba website, but did not find anything. Does this sound familiar to anyone? Thanks.