I have a Lenovo Thinkcenter i7 M92 that worked a while ago and when I turned around to work on another computer, it apparently turned off and now the power will not come back on. The power button wont even light up, nor will the lights where the network cable plugs in. Have tried different outlets, different power cords. I am thinking it is a power supply issue but I cannot find a power supply to order. Any suggestions would be greatly appreciated.