93 Chevy truck with "NO" spark?

[beavis]

I have a "93" chevy truck with a 350 auto tranny. I have no spark, I have done all easy stuff first. like, new plugs, wires, cap, rotor, coil, even tried a new distributer (complete with cap & rotor, pick up coil, and module). I bought a used ECM at the local junkyard. still no fire in the cylinders. I was reading your other letter about no spark and checking the white wire at the coil, will try the later today.

thanks