Fezmid Did replacing the board fix your issue?? I've just conducted the same tests as you did, and same results, continuity in the wire is fine and the magnet reads at 4.5 ohms. Too give a little background, this happened to me before, I contacted Stern and they sent out a replacement board. Seemed to work maybe for a month, and now back to the same issue. Fuse blows once I turn on the pin.
Any other suggestions folks?