You might want to shut off the breaker and check for a loose
connection on the AC power outlets in the kitchen. You may want to
replace them if the they don't hold the plug tightly. They should be
less than a $1 each. Figure they were last served in '81 - that's 24
years ago.

Also, if your boombox has batteries install, you may want to remove
them if you're only using it on AC.