If you power up a 7200 and it always tries to dial out to the MSN server it is because it has a software problem and it is trying to get software to re-initialize itself. It you let it dial out and it is still unable to get its software it is likely that the hard disk has failed. If that is the case you get get a new hard drive and install it yourself and let it dial out and get its software.
Note: the 7200 does NOT need to be connected to the satellite dish to get its initial software (it gets it via the phone line from the MSN server). Only after it has it will you be able to get to the signal strength (dish pointing) screen.