Is This Circuit Board Corroded?

Discussion in 'Effects [BG]' started by dxb, Aug 22, 2019.

  1. dxb


    Dec 25, 2016
    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!

  2. bassinflorida

    bassinflorida turn that dang thing down

    Jan 27, 2014
    Tampa, FL
    Corrosion might not be the term everyone would use, but I would be trying to gently remove the crap lying across the traces without damaging the traces, if possible.
    Rabidhamster and dxb like this.
  3. HalfManHalfBass


    Jan 21, 2003
    It only looks like the sticky residue left from the flux contained in the solder to me.
  4. Looks like flux, nothing to worry about unless it stops working which it probably won't.
    packhowitzer, Bboopbennie and dxb like this.
  5. 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?
    mexicant and dxb like this.
  6. Sanj


    Oct 16, 2014
    Likely dried flux. Try some isopropyl alcohol on a q-tip to clean it, if you like.
  7. akrachanko

    akrachanko Supporting Member

    Mar 9, 2014
    Western Pennsylvania
    Isopropyl on a toothbrush works wonders as well. I found the cotton gets stuck on the component leads.
  8. Sanj


    Oct 16, 2014
    Good call, that's actually what I usually use.
  9. I wouldn’t accept a new device that looked like that. I’d send it back.
  10. boomertech

    boomertech Frank Appleton Commercial User

    Apr 8, 2009
    Syracuse, NY
    Designer/Owner of FEA Labs
    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.

    Spidey2112 likes this.
  11. john m

    john m Supporting Member

    Jan 15, 2006
    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.
  12. 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...
  13. Rabidhamster


    Jan 15, 2014
    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.
    Frank77 likes this.
  14. TheReceder


    Jul 12, 2010
    these things work great... just hack the hairs shorter and then scrub with alcohol.

    giacomobass and Rabidhamster like this.
  15. micguy


    May 17, 2011
    A toothbrush just moves the flux around - the nylon fibers don't absorb well at all. The cotton actually absorbs it, so you get rid of most of it.
    Rabidhamster likes this.
  16. 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.
  17. TinIndian

    TinIndian Supporting Member

    Jan 25, 2011
    Micco Florida
    I'm a manufacturing engineer. That is flux residue with some sort of contamination in it. The above posts are correct, clean it with a little isopropyl alcohol and it should be fine.
  18. pgpete


    Nov 18, 2018
    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.
  19. john m

    john m Supporting Member

    Jan 15, 2006
    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.
  20. Yup, Flux residue. I'd clean it with alcohol before you put it back together. Just for the heckovit
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