I think I may have stumbled on to the problem. My speaker was doing the same. Light came on, speaker plugged in, it would turn on momentarily but then shut off. It’s been like this for months and I simple couldn’t bring myself to throw it out. I tried to turn it on today, but no power. Looked for the power cord but couldn’t find it. I borrowed the power cord from my Bose speaker. It has the same connection. Plugged it in…It freakin works. Amazing! It looks like, at least my problem was not a bad speaker, but a bad charging cable.