About 2-3 years ago I changed out the battery in my DA wireless SRM after is appeared to be dead flat. It was hit and miss as to whether it was being detected. A colleague fitted it to his bike and couldn't get it to detect. Not long after that the bike went into hibernation for some time. I don't think a magnet was fitted after that so I don't think there was anything to wake it up.
Fast forward to now when I want to start using it again. I figured it would be dead. I opened it up per above pic and put a volt meter onto it. It's reading around 3.5V at the battery terminals and at the circuit board where the battery terminals connect. Over at the sensors (wired to the outer cap) the circuit board at the base of the green wires is reading around 1.7V but there appears to zero voltage where the blue wires connect to the circuit board. I've been swiping a typical bike magnet back and forth across the cap where the green wires meet the cap, but nothing is pairing on the vintage Edge 705.
I don't really know the ins and outs of the SRM (what the blue and green pairs of wires represent) and in particular what sort of voltage should be reported at those locations. Before I go down the path of disconnecting the battery and soldering in a new one I thought I'd check first as to whether there's something else I should check/try first.
Cheers