My Wyze scale, purchased April 2020, suddenly stopped working recently. I thought maybe batteries, so I swapped out the old ones for new, but still nothing. Since it was out of warranty, I went ahead an ordered a new one (via Amazon, for same day delivery), and decided to see what could be salvaged from the old one. I pulled the batteries and took a look in the battery compartment, removed the two screws, and tried carefully prying the unit apart. That didn’t work, so I checked with a magnifying glass for anything else that might be holding it together. That’s when I noticed a very slight hazing on one of the negative spring contacts. I used some vinegar to clean it up, put everything back in place, and it works again!
I’m VERY surprised that a very tiny bit of battery corrosion, which didn’t show up on the old battery at all, and was only visible under magnification, would cause the scale to stop working. But I’m very happy to find it working again now, and I will keep a close eye on batteries from now on! Oh, and I will keep the new one as backup, just in case.
Exactly what happened to me as well, except for attempting to disassemble.
Swapped out batteries, checking the voltage on all the batteries. No on switch, no reset button… I got on the net and found your post. I couldn’t find any corrosion on dead batteries or terminals, even with a lighted 4X magnifying lens, but I was hopeful and wiped down all the metal contacts with vinegar.
Voila, My scale works again.
Thanks very much
I’m so glad I stumbled upon this while trying to figure out why my scale would just not turn on. Did the vinegar trick and it turned on right away (with new batteries of course, since that was my first inclination), thank you for figuring this out!
Glad to find this topic before purchasing another one. Cleaning with a bit of white vinegar did the job.
Thank you
Old post, but want to show appreciation for the simple fix. Vinegar is the nectar of the God’s. lol. Thanks to OP for the simple solution to my problem.
Thanks for this post as well! My scale stopped working, noticed corroded batteries, so replaced them all with new ones, the contacts looked fine but still no luck. So googled and this was one of the first hits. A q-tip and some vinegar cleaned it up and presto, back in business!
The only problem now is that I’ve clearly gained some weight. 
Thank you! Found this with Google. Couldn’t see any corrosion but cleaned with Deoxit. Now it works like new.