1. Agilato

    Agilato GBAtemp Fan
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    Kapton tape has smell, when glue is melting. I really like regular aluminum foil.

    My bad to advice wrong temps, definitely for chip re-flow 480C is to extreme.

    Just checked my station, i have 420C in my settings for chip re-flow(not a 480C) on Switch.
    Also i measured temps on a tip of the nozzle, my multimeter shows 400C with air flow 5.

    - There is direct correlation on temps: faster air flows -> colder it becomes when it reaches the point.
    - Ambien temps has very huge effect on actual temps at pointed area.
    - Quality Flux makes difference.

    I think good advice at this point would be to get some broken stuff an practice before trying on actual board.
    You have to have feet to the temps and flows. Different setups for different size of the elements you work with.
     
    Last edited: Jan 14, 2020
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  2. Spawnaor1

    OP Spawnaor1 Member
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    Thank you so much!
     
  3. SlegBE

    SlegBE Member
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    Hi,

    Look at this video from My Mate Vince:

    At 27' even if he has used Kapton, plastic connector nearby the chip has melded

    So, use a lot of protection for these connectors.

    Beleive me, it will be very difficult if you have no experience and good material.
    Good luck
     
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  4. The Real Jdbye

    The Real Jdbye Always Remember 30/07/08
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    He said in one video he thought Kapton tape could actually make things worse, because the heat blew underneath and got trapped underneath the tape. I guess it takes experience to know when is the right time to use Kapton tape.
     
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  5. Agilato

    Agilato GBAtemp Fan
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    Main reason why I never use Kapton tape + it has nasty smell when you heat it up.
    BQ is not an easy chip to replace because of connectors.
    But i found specific pattern how to blow air, that would't melt plastic around.
    Use thin nozzle (4, 5mm) and if you have preheater that would make a huge difference.
    You don't have to aim directly on top of the chip, just take slight left and condensed heat will do the rest.
    Obviously in this case very low temps will not work.
     

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    Last edited: Jan 17, 2020
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  6. Spawnaor1

    OP Spawnaor1 Member
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    Thank you. My chip has not come in yet so have not got a chance to do this..

    — Posts automatically merged - Please don't double post! —

     
  7. Spawnaor1

    OP Spawnaor1 Member
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    So heat around 420 and what do you suggest for air flow from 1 to 10? Ty
     
  8. The Real Jdbye

    The Real Jdbye Always Remember 30/07/08
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    Air flow around half, maybe 5/10 seems good from what I have seen of people soldering on YouTube. 420C looks like it might be good, but you should play around with the heat to get a feel for how hot it needs to be with your particular iron, the part you are working on, how much metal there is drawing the heat away, and the type of solder (lead free which is what is always on manufactured board needs a higher temperature than leaded) etc... There is no one answer for which temperature is right, there are too many factors. 300 something C might be good for one thing, another might require well over 400C.
    As he said, with a preheater much less heat is needed with the hot air station and something like 300C or a little above it would be enough because the board is not taking all the heat away from the part you're trying to work on.
    It is better to start too low than too high because if you start too high you run the risk of delaminating and/or burning the board. Without any personal experience with hot air I hesitate to tell you what exact temperature(s) you should try though. I want to say 380C might be a good starting point, and going up from there if necessary, moving the nozzle in a circle and giving the chip a very gentle tug or push with tweezers every now and then, but it's hard for me to say how long you should wait before assuming the temperature is too low and turning it up, and leaving 380C of heat on it for too long, if it's not enough heat to melt the solder, it might still be enough heat to damage the chip.
     
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  9. Agilato

    Agilato GBAtemp Fan
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    100% agree!
    This is small portion of the board and it will not loose heat that fast so you can go lower temps such as 380C and 5 out of 10.
    Problem is that we really can't give you an exact temperature, there is a lot of variables as i mentioned before.
    This chip it self is easy to replace but environment around it is ver crowded with plastics which you can melt.
    You have to practice on similar looking boards, to have a feeling of your soldering station.

    Firstly use distance and preheat the board. Farther your air-gun from the board cooler temps reaches the board.
    Play with your station, use low temps and hand to understand how temps are changing based on distance.

    On 380C you can start from far distance and preheat all board till it will feel heated up, and than closer focus on specific area i pictured.

    Again do not rush the process, make sure there is no plastic stuff under air gun nozzle, it heats-up quiet hot and will melt stuff also.
     
    Last edited: Jan 22, 2020
  10. krackpack

    krackpack Newbie
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    I had 2 switches do this same thing. I found a cap that was near the usb-c that had no continuity and i used my solder iron and reheated them and it started to charge again. The other one i bought offline broke. But inside there was a few caps that looked liked they were burnt a bit and i replaced them and it works now
     
  11. Spawnaor1

    OP Spawnaor1 Member
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    Cool thank you!
     
  12. Spawnaor1

    OP Spawnaor1 Member
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    Thabks to everyone. I tried to remove the BQ chip but no luck. I tried different temps from 360 to 480 and no luck. The solder would not melt. The speed of the air was 3 out of 10. I ended up putting it back togetherto sell for parts and it now works! Dont know what happened but maybe the high heat on the board did something.. Thabks to everyone
     
  13. The Real Jdbye

    The Real Jdbye Always Remember 30/07/08
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    In those cases you can try turning up the air flow. Big ground planes or big pads with lots of solder will sink away a lot of heat quickly so heat has to be applied faster than it can sink away and with low air flow you can only put so much heat in at once. Also, depending on the quality of your hot air station it may not be able to reach the temperature stated, as it does not have enough wattage/thermal mass to keep up with the air flow taking heat away.
     
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