U5000 "singing"

Working on a 25" U5000, Power it up and it makes a hissing/singing sound.

I have verified the power supply section is good (isolated the section by
pulling the output wire up and hooking it up to a lightbulb, B+ right at 118
that way).

I verified the HOT is good.

I figured the flyback was arcing internally so I swapped it with another.
Same sound.

B+ is up over 220v, so there is something wrong, but I am not sure what.

Same noise in 15khz or 25khz modes.

Suggestions?

Thanks,

David

---------------------------------------------------------------------------
** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org
** Please direct other questions, comments, or problems to chris@westnet.com
Received on Wed Nov 21 04:48:24 2012