Well turns out I fixed it on my own. On the back of it the rectangular sticker hides 2 screws, and under the round sticker on the spindle is another screw. Unscrew all three and pull open the housing. There's 2 more silver screws holding the green printed circuit board down.
The small black switch that sits against the rotating center hub spindle you can hear it click as you rotate the metal probe needle to turn on the unit. It looked pretty solid to me, but on the other side of the PCB was a tiny transistor that looked under my 10x magnifier, like maybe one of the 3 legs was iffy on the amount of solder, but I just pushed it back down on the solder pad and put it back together and now it works!
Not sure if that was the problem or if there was some loose shrapnel that got caught inside the black switch mechanism preventing a good turn on.
While I had it open I used a white plastic pencil eraser to clean the battery contacts and one of them broke, so it may have been cracked and not making good contact. Stuck some foil in on the ground side of the battery to complete contact.
Either way, ready for turkey day now.