Contour remote won't turn audio receiver back on

I have an older Harman Kardon audio receiver. I programmed my Contour remote using one of the five digit codes provided for Harman Kardon receivers. The All Power button turns the TV and receiver off. When I press the All Power button again, it turns the TV back on but not the audio receiver. I tried all of the five digit codes that I saw listed and none of them work to turn the receiver back on.