TRACON Controller described a MVA violation immediately after assuming the position; distracted by frequency issues resulting from position configuration/s; the reporter indicating the relief should have been delayed temporarily.

Narrative

I was relieving another controller. Prior to accepting the position he descended an aircraft to 2;700. The aircraft was being vectored for an approach to a satellite airport. The aircraft was approaching the edge of our MVA that goes up to 3;000. I figured I had enough time to turn the aircraft before it got to that border. Unfortunately after sitting down there was a problem with the frequencies. We had just split off another sector and the frequencies had not been configured properly. Then there was a question about a RADAR outage that diverted my attention to our IDS display instead of watching the scope. By the time this was over the aircraft had already went beyond the 2;500 MVA and into the 3;000 MVA. I immediately turned the aircraft back toward the lower MVA but did not climb the aircraft back to 3;000. Recommendation; I will never accept a position again until all issues have been worked out. In this case I should have stepped away until the frequency issue was cleared up and allowed the previous controller to turn the aircraft onto the approach.