In article .com,
"nortonfan" wrote:

I've replaced the blown diodes and the protection fuse and powered the
unit. It makes a rather annoying buzzing sound, not as loud as an old
doorbell buzzer - but, annoying, nonetheless.

Norman-

If the power rectifier diodes were blown, I would suspect that any filter
capacitors associated with the output of the diodes might have also been
damaged. Obviously they aren't shorted, or you would have blown more
diodes!

As you have noted, Bulova is a watch company. They may have had some
other company make the ultrasonic cleaner for them. A little research
might turn up two or three companies that have produced them, and there
may be a model that looks identical to yours.

Back in the 70s I built the Heathkit GD-1150 Ultrasonic Cleaner. The
operational test was to use a 1" strip of aluminum foil held vertically in
1" of water, and expect a minimum of ten pinholes created in the foil
after 30 seconds of operation.

Fred