I have a Pio SD-582HD tv (58" Pioneer Rear projection HD) I am using a DTC-100 VGA to VGA

I had to the TV ISFed a couple months ago and I just touched up the SD convergence in all SD modes. I bought a Key Digital transcoder just do adjust my HD convergence as the TV won't adjust from VGA ,HD needs to input to component for adjustments. I have all the dips on the Key Digital correct but I get a black screen? I also get a very loud hum when using the input the Key digital is hooked up to. I have it set to Pos. sync and regular. I did buy the Key Digital used so I don't know if that is the problem. I have it set for 1080i and no matter what I change for sync still black screen. It is hooked up to input 3 and I have moved the switch for input 3 both ways and still no go. Any ideas?