RMDM46 Can't Find Signal

[gmatlock]

I have recently changed from Direct TV to Dishnetwork and I hooked up one of my receivers to the RMDM46 dish but I can't find a signal. Reading through the forum I found a similar issue and I followed the instructions listed changing the dish 500 to the dish 300. I did that but I still can't find a signal. I reinstalled the direct tv receiver just to check the system and it easily finds the direct tv signal. What must I do. The system is advertised to work with either direct tv or dish network.