my only suggestion would be to take fine steel wool to the three stainless sensors then do the acid clean again. I've had one crap out on me also, then got a replacement and it was bad from the get go. The new one that they sent to replace that did work though. They seem to be rather sensitive. You can call Jandy and speak to the tech service people, sometimes they are helpfull. I've managed to con the professional tech service people at Jandy a couple of times and they are very helpfull compared to the homeowner tech service folks. Depending on the rep, most of the pro tech people won't help you when they find out you are a home owner. Bottom line, I think you are in for a new trisensor if the extra cleaning step doesn't work. Occasionally you'll find a bargain on ebay for one.