I come to you, needing help...

I have a Mac IIsi that, up until a week ago worked like a charm, happily frolicking through meadows, hand in hand with System 7.5.5. But, for some reason or another, it has died. I really have no clue how or why, but it is dead, it is as good as a paperweight. There is no response when the power button or reset button is pressed, not even a fan flicker :?: .

Thanks to all that can offer insight or help.