rework station

Discussion in 'General Electronics Chat' started by johndoe45, Aug 11, 2011.

  1. johndoe45

    Thread Starter Member

    Jan 30, 2010
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    quick question. i just bought an aoyue 968 rework station

    however the soldering iron is only 35W temperature controlled (200-480°C). is that enough power to desolder a cap off an xbox 360 motherboard? cause i read somewhere that even someone with the aoyue 2702 with a 70 watt iron (200-480°C) had trouble desoldering something.

    i've used a radioshack 35 watt and couldn't get it off with lots of flux. and also a big solder gun but the tip was too large so i didn't go through with trying to take it off
     
    Last edited: Aug 11, 2011
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Sounds like poor operator skill.. A true 35W iron should easily be able to desolder a capacitor.. No idea why you have to use flux to "remove" a soldered part.. Flux is commonly used to remove oxides on the leads/surface "prior" to soldering not in the removal process.
     
  3. johndoe45

    Thread Starter Member

    Jan 30, 2010
    364
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    alright nice. so this one should do. thank you for the quick reply mcgyvr
     
  4. PatM

    Active Member

    Dec 31, 2010
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    If the iron doesn't seem to work, and you are using discrete components, sometimes just clipping the lead to the part helps.
    That way you are only heating up the short lead and not transferring heat to the component as well.
     
  5. Stuntman

    Active Member

    Mar 28, 2011
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    You should be fine with 35W, I"m not familiar with XBox 360's, but my guess is they are lead free, which makes the molten point higher and therefore harder to desolder. Set your iron hot, and remember to tin the tip before you try to heat the leads up. Solder sucker is also a nice tool for this type of task.
     
  6. johndoe45

    Thread Starter Member

    Jan 30, 2010
    364
    1
    just got my aoyue 968 yesterday.

    still having trouble desoldering things off xbox 360 board.
    using the default tip on the station which i know is pretty thin, I still can't desolder anything.

    when i try to melt the lead solder onto the lead free solder to lower melting temp it just makes a ball and slides off. then using flux. still no luck.

    the max temp i have tried on the aoyue is 400°C on the iron which is way too high

    WHAT AM I DOING WRONG?

    Also trying to remove a mosfet with the hot air is a no go. can't seem to do that either.
     
  7. strantor

    AAC Fanatic!

    Oct 3, 2010
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    theres probably a conformal coating over the solder preventing heat transfer. use sandpaper or other abrasive gently rub off this layer and try again. it also helps to put a little solder on the tip of the iron beforehand .
     
  8. johndoe45

    Thread Starter Member

    Jan 30, 2010
    364
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    sanded down one of the mosfets legs. 300°C soldering iron with tinned tip. nothing. frustrating. maybe should make a video tomorrow of the whole process i am doing cause this is ridiculous.

    like i said before soldering iron is only 35W. maybe i need to hold it there for like 20 seconds or something? i thought you weren't supposed to hold tip for more than like 2 seconds or can damage pads and whatnot
     
  9. strantor

    AAC Fanatic!

    Oct 3, 2010
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    may be that these pins are soldered into planes. I have run into that before; the ground planes are huge heat sinks that sap all the heat away from your iron. very frustrating. The way I got around was is just to cut as much of the component away as possible and hold the iron there till it came free. maybe 30 or 40 sec. at the time I figured I had no other choice. came out fine, no damage. Wait around for some input from more experienced solderers, maybe we can learn a trick together.
     
  10. Stuntman

    Active Member

    Mar 28, 2011
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    When I desolder, I prefer to take the tip temperature as high as possible, tin it quickly, contact the part and solder mound to melt, then pull the part lead by lead. (with a hot air gun, this is much faster, but is quite prone to ruining PCBs). I've desoldering far too many commercial boards with this technique.... and this was using a 35-40W iron.

    Is the solder simply not turning molten? It sounds like you are tinning your tip right?

    I must add, many commercial boards seem to have the parts either snapped into their holes, or adhered somehow to the board on the component side. I assume you are not trying to salvage this old part, so I would suggest doing some wiggling of the part while heating the pads to get the leads broken free. Desoldering especially lead free parts, is not a fun endeavor.
     
  11. johndoe45

    Thread Starter Member

    Jan 30, 2010
    364
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    here is a link to the video at 400°C i believe. this was after the solder blob finally stuck to the lead free solder.

    http://www.megavideo.com/?v=EN1EYF7R

    the camera jumped when using the solder sucker cause i had it laying on the pcb. lol

    so basically the 400°C soldering iron only removed the blob and couldn't melt the lead free solder still.

    RMA the unit? or what is the deal
     
  12. tom66

    Senior Member

    May 9, 2009
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    Have you tried using some desoldering wick or a solder sucker? Is it an SMD cap or a through hole one you are trying to remove?
     
  13. johndoe45

    Thread Starter Member

    Jan 30, 2010
    364
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    through hole as in video. haven't tried desoldering wick. i have one but always burn board a little so i bought a desolder sucker about year ago and been using it since. this lead free solder is stubborn though
     
  14. tom66

    Senior Member

    May 9, 2009
    2,613
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    Try using wick, seems to work better for some devices. Heat up the joint with the iron set to around 350-400°C. Put the wick next to the joint. Solder will flow from the joint.

    Note, some boards use a solid ground plane with no thermal relief. In which case you will find it difficult to remove the capacitors, you will just have to heat up the joint for a long time until it starts flowing.
     
  15. johndoe45

    Thread Starter Member

    Jan 30, 2010
    364
    1
    about to take off. will try this later. thanks tom66 for all your help.
     
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