In article , Jim Adney wrote:
On Tue, 24 Jun 2008 21:28:04 -0400 "Dan Dubosky"
wrote:

Good point, Mike. There may have been something on the cell phone board
that was not on my experimental board. I did however scrub the cell phone
board twice with Radio Shack Electronics Cleaner and I think that there is
still some effects left from the submersion.

It sounds like you've been careful and thorough, but your board might
benefit from additional scrubbings in some other solvents, since not
everything is soluble in Radio Shack Electronics Cleaner.

In general, I clean things by starting with clean water, since it is
the most universal solvent. If it is really dirty, I may start with
soap and water and a toothbrush. Then I follow up with clean water,
then distilled water, and finally alcohol, and I don't worry about the
fact that it isn't 100% alcohol.

I have cleaned stubborn high impedance loading by using mostly alcohol
and the Weller air pencil set to a high flow and low temperature. The problems
were under the components. I sometimes have to repeat many times
before all the flux and residue is out. You have to move the air pencil around
under components, going mostly in one direction. The old boss made me use alcohol.

By the way, the cell phone I worked with appears to be OK after much cleaning, cyclic baking, and
a month delay.

greg