I found a YouTube comment that suggested that one needs to periodically push and forcefully rotate the power button side of the trackpad clockwise. I bought a used one that had initially some battery corrosion but worked, and eventually started to have frequent disconnects and then failed to turn on. I cleaned any of the corrosion out of the battery compartment but it still would not turn on. I tried the method of forcefully rotating the power button clockwise with my finger and after a few attempts to do this, the trackpad started working again and now no longer has repeated disconnects. I found this out only after purchasing two more shattered donor trackpads on eBay to use for parts in case mine was corroded and that caused the failure. I will take those two apart in more detail and see if there is anything to be learned about the power button assembly.