help! beginner's desoldering error- is this ruined?

Discussion in 'General Electronics Chat' started by nickboyroy, Apr 26, 2014.

  1. nickboyroy

    Thread Starter New Member

    Apr 26, 2014
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    Hi,

    I've just learnt a lesson the hard way while trying to remove a voice chip from my Juno 106. I couldn't remove it so gave up. I then realised I may have damaged the pads. What was I thinking!

    Please could someone take a look at the mess and tell me if it's repairable with a new socket?

    The board still works as before. The chip is dead like before however this is not too important. It's whether a new one could be placed in the board and the old one removed.

    Thank you for your time! The pictures were the best I could get last night but I'll try and get some better ones.

    Cheers

    Nick
     
  2. t06afre

    AAC Fanatic!

    May 11, 2009
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    The picture is to blurry. Do you think you can take some new ones that are more sharp :)
     
  3. Wendy

    Moderator

    Mar 24, 2008
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    Use pure IPA (90% pure isopropyl alcohol) and a basting brush to clean up the board and remove the flux.
     
  4. nickboyroy

    Thread Starter New Member

    Apr 26, 2014
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    Hi thank you for your reply. Are you saying clean it and repost pictures? I have white spirit. Can I clean it with that?

    I've uploaded another picture. But without cleaning.
     
  5. MaxHeadRoom

    Expert

    Jul 18, 2013
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    If the board had conformal coating of any kind, this needs to be removed with a conformal solvent to be able to work on it without damage.
    Max.
     
  6. nickboyroy

    Thread Starter New Member

    Apr 26, 2014
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    i don' think it had a coating - the chip removal is a commonly done with a desoldering gun or brade i've been told.

    here are some better pictures.

    I'm hoping it can be removed - the chip - and a socket added .

    it's an expensive mistake if not!
     
  7. atferrari

    AAC Fanatic!

    Jan 6, 2004
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    Maybe the chip is soldered on both sides. Could you show the other side?

    Daylight, cloudy day, take many pictures and select the best.
     
  8. nickboyroy

    Thread Starter New Member

    Apr 26, 2014
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    Hi,

    I've uploaded some pictures, it's really difficult to photo due to its positioning on the board.

    So i've added a picture of a different chip with the identical soldering.

    All components appear to have pads on the other side, with solder.

    Does this mean i've dodged a bullet and can send it off to a professional? I hope so! I'm leaving soldering circuit boards alone for a long time now i think!!!

    thanks for your help on this by the way!

    Nick
     
  9. nickboyroy

    Thread Starter New Member

    Apr 26, 2014
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    here is one with labelling
     
  10. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    hi nick,

    Did you try to de-solder and remove the IC in one piece.?

    If the IC is know to be totally useless, the best way is to snip of the legs of the IC one by one. Leave enough cropped pin lead to enable gripping with a pair of fine pliers.

    Then desolder each cropped pin and pull out the pins as you go.

    If you dont have desolder gun or wick , use the pointed end of sharpened match stick to clear the holes of solder.
     
  11. nickboyroy

    Thread Starter New Member

    Apr 26, 2014
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    0
    Hi,

    I've found someone who will service the board so i'm just going to leave anymore DIY!

    I'm basically asking if i've ruined the board?

    Will a professional still be able to remove the chip - doesn't matter if it's broken - replace a new one in the holes i've shown, or is the board broken beyond repair now??

    Many thanks,

    Nick
     
  12. nickboyroy

    Thread Starter New Member

    Apr 26, 2014
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    0
    Hi,

    I don' think my last reply posted - sorry if this has -

    I'm basically just asking if the board will still work - I will send it to a professional now to remove the chip and solder -

    I'm just asking if my attempts have broken it? The board still works in the Synth

    I'm just asking if who ever repairs it will be able to put a new chip in it? and it still work??

    thanks again for your help,

    Nick
     
  13. PackratKing

    Well-Known Member

    Jul 13, 2008
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    Checking in late as usual :D

    The chip, appears to have been mounted in plated through-holes, which are darn hard to damage... and do not appear to be in bad shape... RE: the small pic in # 6 ...

    If one or two are damaged, once the new chip is mounted on the good holes, it is possible to run short insulated jumpers to the next viable part of the trace downstream...

    Future reference... as ericgibbs suggested in # 10 it is best to clip the dead chip out, and deal with the pins separately afterwards...
     
  14. t06afre

    AAC Fanatic!

    May 11, 2009
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    That is correct. But in my experience the tracks may easy be damaged, kind of worn off at the point they connect with with pad. After rough de-soldering. However in this case this can easy be fixed by using wire straps. Soldering them pad to pad.
    As a note to the OP. White spirit is a petroleum product. It is much better to use a alcohol based cleaning liquid. Brush gently with an old toothbrush
     
  15. nickboyroy

    Thread Starter New Member

    Apr 26, 2014
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    This is great news, thank you all for your help. I really appreciate it. Very kind of you all!

    Nick
     
  16. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    If the thru hole plating is 'broken' the its possible on that type of IC to top and bottom solder the pins to the tracks.
     
  17. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    It should be fully repairable, I've fixed worse.

    It is a simple two-sided PCB with large simple tracks. Even the pins where the pad has been ripped free can be patched with some whisker wires to the nearby track.

    A good pro should be able to do that without too many problems. :)
     
  18. ian field

    Distinguished Member

    Oct 27, 2012
    4,415
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    I use cellulose thinners for car paint spray - but beware, its highly flammable!

    It can also damage some components.

    Examine each hole with a missing pad - did it have a track going to it?

    Usually you can scrape the solder resist varnish and tin the track, solder a thin strand (stripped from flex) of wire to the track and feed it through the hole, if there's a track on the other side that went to that hole, solder it to that - otherwise trim it so it can't short anything.

    If its a multilayer board and the damaged vias connect to sandwitched layers - you could be screwed!
     
  19. KeepItSimpleStupid

    Well-Known Member

    Mar 4, 2014
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    Eric has it nailed.

    But, sometimes to remove a chip, I add solder, but don't let it cool before wicking or sucking it out.
     
  20. ian field

    Distinguished Member

    Oct 27, 2012
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    The way I was taught to remove scrap chips while working in the industry, is to snip/shear the pins off at the chip header - the pins are *MUCH* easier to remove one at a time.
     
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