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Is This Circuit Board Corroded?

dxb

Dec 25, 2016
1,534
2,080
I recently bought a new Pigtronix Ringmaster and I noticed some odd residue on the PCB. Just wondering if the experts could tell me what it is and whether I should be concerned about it. Thanks!

P_20190822_073744b.jpg

P_20190822_073933b.jpg
 
That doesn't look like flux to me, unless it's some sort of new flux. I have seen this sort of white haze when the solder joints have been exposed to moisture. I don't know if the white stuff is oxide or the rosin turning white from reacting with water or alcohol.
It only appears at certain solder joints- I wonder if these joints were re-flowed by someone using some oddball flux, or maybe a flux cleaner afterwards?
 
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I recently bought a new Pigtronix Ringmaster and I noticed some odd residue on the PCB. Just wondering if the experts could tell me what it is and whether I should be concerned about it. Thanks!

View attachment 3516056
View attachment 3516055

It's flux residue that wasn't completely cleaned. 91% Iso with an old toothbrush will remove it as was stated above. Just keep power off of the pedal for about an hour to be sure all of the water to evaporate. If you use a tech grade of 99% Iso you can power up after a few mins.

-Frank
 
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That doesn't look like flux to me, unless it's some sort of new flux. I have seen this sort of white haze when the solder joints have been exposed to moisture. I don't know if the white stuff is oxide or the rosin turning white from reacting with water or alcohol.
It only appears at certain solder joints- I wonder if these joints were re-flowed by someone using some oddball flux, or maybe a flux cleaner afterwards?
Looks like flux on the hand soldered components.
Lots of “new” flux — been out for about 20 years, is more environmentally friendly.
Some are water soluble, but can be cleaned with alcohol.
Old school flux usually leaves yellowish residue.
 
I don't recommend opening any of your common, run-of-the-mill electronics to take a look inside, then.

...or perhaps my sarcasm radar is not working? Better go check for cold solders/flux residue on contacts...
The number of items with dried blood inside them when you take them apart is shocking. I used to find it regularly in brand new PC cases. Found it inside a toaster, as well. Fun to see how the items we take for granted are actually built.
 
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Looks like flux on the hand soldered components.
Lots of “new” flux — been out for about 20 years, is more environmentally friendly.
Some are water soluble, but can be cleaned with alcohol.
Old school flux usually leaves yellowish residue.
I bought some solder once that had what was supposed to be a water soluble flux. It had a sickly sweet smell to it when soldering, so I decided to look up the MSDS on it, and found it contained benzine. I got rid of it and went back to tried and true rosin flux.
 
As someone who did high reliability soldering back in the day - I dont like the way the soldering has been done on this board.
you can see that they poked the component wires through - soldered them and cut off the leads afterwards. this exposes the join where dissimilar metals are bonded - the galvanic reaction between the two metals can lead to corrosion in the solder joint.

its better to cut the lead to the desired height and then do the solder joint which seals the joint - reducing the chance of oxidization.

also - just clean off the flux with iso-propyl alcohol and toothbrush and then a lint free wipe.
 
I bought some solder once that had what was supposed to be a water soluble flux. It had a sickly sweet smell to it when soldering, so I decided to look up the MSDS on it, and found it contained benzine. I got rid of it and went back to tried and true rosin flux.
Fortunately, industry is regulated to what goes down the drain and into the air, particularly with the solvents needed to wash the solder joints during production.