Electronics: Is it ok to weld a wire directly to the board ?

Discussion in 'Community Discussion' started by XPcentric, May 2, 2017.

  1. XPcentric macrumors 6502

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    Oct 16, 2008
    #1
    I broke one pin of the little piece that the fans connector goes into on my macbook, its called 4pin fans connector. The fans still work with a little bit of applied pressure.

    I went to a computer repair shop and told them that I can order that piece. But it would take a long time to arrive and I will pay more in the end. He suggested he can weld the wire from the fans directly to the board. He also said that it could heat up the way it is now, the way I improvised. It will all cost 5 euros.

    Should I follow his advice or should I order that 4pin fans connector ?
     
  2. Scepticalscribe Contributor

    Scepticalscribe

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    #2
    Order the four pin fans connector, and pay the piece asked. What is meant by the expression "a long time" by the way?
     
  3. XPcentric thread starter macrumors 6502

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    #3
    it can take at least 40 days for that parcel to arrive. And its only possible to buy bulk of 3 pieces minimum but I only need one piece.
     
  4. Scepticalscribe Contributor

    Scepticalscribe

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    #4
    Well, when you receive it you know that you have the exact piece of equipment that is required.

    And - you will receive two extra pieces, in addition to the one you need? Well, then, you have spares if something breaks (again). Keep one, and sell one on eBay, if you are into that sort of activity.

    Meanwhile, look upon the temporary solution as something that you hope will last for the full 40 days; I cannot see how you might envisage it as a permanent solution, anyway.

    And - how much is this transaction expected to cost you?
     
  5. Huntn macrumors G5

    Huntn

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    #5
    You were messing around with the guts of your Laptop? o_O;)

    I am unaware of a problem/future complication with soldering a wire to the motherboard, is there? But it's now a permanent vs a modular connection. My choice would be to keep it modular if possible with your needs accociated with your computer. Do you have another computer to use in mean time?
     
  6. AngerDanger, May 2, 2017
    Last edited: May 2, 2017

    AngerDanger macrumors 68030

    AngerDanger

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    #6
    It might be helpful to ask what the repair shop employee would do if it were their computer with the same issue ("I don't know… what would you do?"). People tend to provide less dubious options when they're the ones facing them.

    As for the potential issues that might arise from soldering directly to the board, I've seen the solder pads get completely melted away, making it impossible to make contact without modifying the whole board as seen 7 minutes and 38 seconds into this video (you can jump directly to that point here):

     
  7. Mousse, May 2, 2017
    Last edited: May 2, 2017

    Mousse macrumors 68000

    Mousse

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    #7
    If it's an Apple LB (logic board), then any replacement LB in the future would cost full price, since :apple: won't accept a modified LB in exchange.

    What *I* would do is find another 4 pin connector, clip the wires and solder it to the fan. Fans are usually not an exchange part.
     
  8. XPcentric thread starter macrumors 6502

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    Oct 16, 2008
    #8
    ok, thanks everyone for answering, I think Ill keep it like it is for as long as possible because it still works. I was thinking about the posibility of getting the board broken if the person who does the work is not too experienced. However I believe that the person is experienced as he deals with mobile phones and computers and can weld tiny pieces and I think he has special tools.
     
  9. bunnspecial macrumors 603

    bunnspecial

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    #9
    I hate to be a stickler, but I'm just going to mention that welding and soldering are VERY different processes. About the only thing they have in common is that they are used to attach metal pieces together.

    The thought of welding a wire or connector to a LoBo sends a shiver up my spine.
     
  10. hallux macrumors 68020

    hallux

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    #10
    I was thinking the same thing. Any shop that says they want to "weld" on a circuit board is one I'd be running from, and I don't run...
     
  11. bunnspecial macrumors 603

    bunnspecial

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    #11
    Agree completely.

    Just to expand a little bit, soldering makes a mechanical and/or electrical connection(depending on the context) using a metal alloy with a much lower melting point than the substances being joined together. For electrical work, the piece can be heated by applying current to the parts to be joined and letting their resistance heat the surfaces(resistance soldering), but heating the surfaces to be joined with a soldering iron or other hot object, or by heating the surface with hot air. Resistance soldering is rarely used on sensitive electronics for obvious reasons, although it's a great technique for plain electrical soldering. Heating with a iron is used for intermediate sized electrical work and some larger electronics work(a soldering gun is sometimes used for larger electrical jobs) while hot air is often preferred for surface mount components. There are types of soldering that are used for mechanical applications-probably the most familiar ones are in plumbing and jewelry work, and these often use a low(er) temperature torch for heat.

    (Metal) Welding involves melting and joining the metals themselves together without the use of a filler alloy. Needless to say, it's a much higher temperature operation. There are bunches of welding techniques, but a lot of the more common ones can be distilled down to either using a very high temperature flame(i.e. oxy-acetylene) or using using an electric arc. Needless to say, you don't want either of those anywhere near a circuit board.
     
  12. chown33 macrumors 604

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    #12
    I've accidentally used arc-welding on circuit boards. This usually involved failing to discharge a capacitor of significant size before undertaking repairs.

    The least bad outcome was when the wire tip vaporized, leaving a small "blast" mark on the copper. The worst was when it vaporized several copper traces and an IC.

    There was also one time when the wire bonded to the copper (a successful weld), which I count as worse than the vaporized wire tip, because then I had to dike out the welded wire.
     
  13. D.T. macrumors 604

    D.T.

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    #13
    Thought the OP was DIY'ing this, saw the word "weld" ... sat back and waited for hilarity to ensue :D

    I've done my share of component swaps, usually [cheap] caps on a logic board - we've got an old 23" Samsung LCD panel, fixed for ~$5, and our not inexpensive fridge had a cap go bad about a year OOW, bought a replacement board, but later fixed the original, swapped the original back in, got a backup board :) Again the fixed board cost about $8.

    I usually use mouser.com

    I'm thinking about trying to reflow a surface mounted chip (DSP processor) in an AVR, if it gets nuked, I'm prepared to replace anyway (just going to cook it with a heat gun).
     
  14. Stefan johansson macrumors 65816

    Stefan johansson

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    #14
    Trying to repair a modern laptop by yourself takes a lot of soldering experience,I would have ordered the spare parts,and instead,if I want soldering practice,do it on the motherboard of my old ZX-80 kit computer. Much less economical loss if I fail.
     
  15. hallux macrumors 68020

    hallux

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    #15
    If you try to weld a circuit board, I anticipate it'd looks something like this (not from an Apple). I took this pic myself, I was not responsible for this damage but I did repair the system with a replacement board.
     

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  16. Stefan johansson macrumors 65816

    Stefan johansson

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    #16
    If you damage it or not,depend on tip size of the solder iron,and your actual skills. But as I posted earlier,trying to repair sensitive equipment with just hobby tools and hobby skills is not worth the risks involved. However,soldering on circuit boards for late 1970s kit computers is not quite that difficult.
     
  17. bunnspecial macrumors 603

    bunnspecial

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    #17
    I think @hallux was referring to the fact that the damage to that board looks like it could have come from a typical welding arc, not the fact that it was soldered with too hot of an iron or other tool.

    A while back, I changed the PRAM batteries on my Mac II board. Unfortunately, my board was one of the early ones for this model that had the batteries soldered to the board. In addition, it is one of a very Mac models that requires a working PRAM battery to boot(many will not boot with a dead battery installed, but are perfectly content to boot with no battery). In any case, I had no issue with getting the old batteries off and new ones in place(once I found the batteries with soldered leads in China). As things go, though, it's a pretty simple repair as the solder leads go all the way through the board.

    Unfortunately, that board had other issues and I ended up replacing it completely(with a new in box Apple service part!). There was actually a service bulletin issued on the early Mac II boards that any which came in for repair with soldered batteries should have them replaced with a battery holder, and my replacement board had such a holder.

    Now that I have a working Mac II, I want to pull an @eyoungren and connect 6 monitors to it. I have enough NuBus video cards to make it happen, although I need to set up the space to do it. System 6 actually handles multiple monitors quite elegantly-the control panel is fundamentally unchanged even in Sierra(albeit it's been "prettied up" a lot from 1980s aesthetics and added a few features) and with some of the cards I have I can get 24 bit color at 1024x768. I'd consider that impressive for a 1986 computer, although you'd have been well into 5 figures to do it then(I think a basic system with a 4-bit color card and a 12" Trinitron was right at $10K) and I also don't think some of my cards were even on the market until closer to 1990.

    All of that aside, I've also repaired key switches on the Apple Extended keyboards, a process which requires unsoldering the switch from the board. These are single layer boards with big traces, so fortunately they're also relatively easy.
     
  18. Stefan johansson macrumors 65816

    Stefan johansson

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    #18
    Well,I never tried to work on motherboards in Apple computers,as a failure would be cathastrophic,but with the old building kit ZX-80,you can,with some experience,easily change components,repair it or modify it.
    But of course,the ZX was sold in electronic hobby stores long before Apple computer company was founded.
     
  19. A.Goldberg macrumors 68000

    A.Goldberg

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    #19
    Agreed x1000.

    I might also suggest to the OP shopping around different places for the actual replacement part, perhaps somewhere that does not make you buy it in bulk or have to wait 40 days. Have you checked with the original manufacturer?
     
  20. bunnspecial macrumors 603

    bunnspecial

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    #20
    It can be done.

    A friend of mine has recently done a lot of work replacing G3 processors with G4s. There are only certain models where it works and even then it's not 100% successful but he can generally get them working. So far, I think he's only done PowerBooks and iMacs, but others have done Clamshell iBooks. He also often has to move resistors to get the clock speeds correct.

    He uses hot air to do his surface mount soldering.
     
  21. Stefan johansson macrumors 65816

    Stefan johansson

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    #21
    Of course it can be done,but it takes lots of experience and knowledge,so I guess I stay with modding old Sinclair computers and stereo amplifiers.
     

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