David Farber wrote:

I occasionally see this residue where the components are soldered. Is this
flux? Something else?

http://www.pbase.com/image/83992679


That is flux residue left after a run through a PC board washer, and
oven dry cycle. I saw it all the time in manufacturing. The ladies that
worked the cleaning room hand cleaned that with IPA and flux brushes, or
with a spray defluxer when they couldn't reach it with a brush.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida