Yuppy,
another day in the hills here, service call, refer & countertop not working, home approx 1970's with BX throughout
( which had been in a barn for god knows how long beforehand...)

the entire cellar had moisture damage, all the bx is rust, and the panel following suit.....

4/0 SEU serv entrance's hole is visible to the outside ( no sill plate) , additional water entry there....

breaker serving outage found and replaced, in doing so i had shut off the 200A main.

On reactivation it sputtered notably as 1/2 the home came & went...the light show lasted about 2 minutes......finally it set.

This all occured with the customer present, whom i suggested a new box.

He simply chuckled and stated he'd 'git ta pluggin' that dern hole'......