I fixed my eTrex 30 using the procedure outlined in "How to unbrick a Nüvi". I first used "updater.exe" lo load a cure xxx.rgn image made with the GarminCure3 tool, then I made and loaded a full yyy.rgn image.
What I missed at first was that you have to hold the stick in the up position during the entire load process. A bit tricky, but it worked.