I have the same (?) issue. Had an ADS1115 running, plug-and-play thing with proper resistors and all. Was getting a normal ADC read-out in the code, and then out of a sudden, Pi 3 B+ freezes, nothing. Disconnected all. Tried to reboot. Nothing. Just power LED constantly lighted, no ACT coming up.
Did the measurements, +5V is all there and good, +3V is not there (measures around +7 mV). What the heck? Any ideas? I have let the thing rest for two days, hoped it was some fuse problem, didn't help.