As for repairing the helix goes, I hope you have some circuit board soldering experience!

As for the base herpstat. I have two pros and would trade my Helix in for a base herpstat anyday! With the helix anything goes wrong and it has to go in for service. That is all fine and good if you have a spare, but if you are the guy that only has what you need you are going to have cold snake on your hands. The herpstat probes are at least a plug in unit so you can swap them quickly!