I don't quite understand the question...
First, a STAR normally ENDS at an IAF; it doesn't usually START at an IAF.
Second, you would normally have ATIS before reaching the IAF, and would also have an expected runway and/or approach. If you lose communications, hold at the IAF until your ETA or EAC. If you have been told to expect an approach on arrival at the IAF, squawk 7600 and continue the approach, unless there are other, airport-specific lost comm instructions.