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Remove Excess of Solder on Tristar IC

Hello I've tried to replace the chip IC Tristar, because my iPhone is not charging, I removed the chip and replaced for a new one, but the iPhone still not turning on. On these processes I used heat, flux, and the replacement was ok.

However, I didn´t removed the solder, from the previous chip from the logic board and when I removed, I saw that the 2 layers of solder (older chip and the new one), was too much.

I buy solder wick, in order to remove the excess of solder (Brand: ProKit´s 1.5mm), as can be seen on the link. But the solder wick is not, catching with the solder, at least is not so easily (sometimes it grabs a little of solder). When I used, the wick, I tried, with and without flux, but the problem stills.

Can someone give me some advices/tips, of what am I doing wrong, or some missing step, that I should be doing?

Another questions is about the, proper temperature that I should be using, and the time that I can have the soldering iron above the board, without damaging it?

Thanks in advance, for any help provided.

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This is really about proper heat transfer.

Obviously flux will help with the heat transfer but if the flux didn't make much of a difference, it is either because your tip wasn't hot enough or large enough. Personally, I set my iron or hot tweezers to 380C, unless I am working on flexes or other "soft" materials. The whole point of soldering is getting the solder/pads to the proper melting point of the solder (Leaded ~185, Lead-free ~217C). However, the size of the pads/components and the underlying pcb (i.e. a ground plane) can cause a huge variation in the amount of heat required to get it to the right temperature. Small tips transfer less heat and if you are working on ground plane pads, it will not be enough. So then you need a larger tip or pre-heat the logic board to ~125C.

As for leaving the old solder behind, the best practice is to remove as much of it as possible but wicking is typically avoided as the pads are very delicate and can easily be removed by the wicking action. To do this, I suggest a concave tip, such as this one. It will literally suck up the solder from the pads. It won't remove all of it but leave just enough behind.

All of this to say that you really need to practice this "art" on dead or donor boards until you get the right feel for when things are done properly or not.

It is also about not trying something new on something of value

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@jifixit2 ... In addition to the good advice @refectio suggested, I have also found that buying some Low melt solder (Chip Quik is what I use) and applying it to the existing solder you are trying to remove can help dramatically! It is great for areas where you do not want to apply to much heat and mixes in with the existing solder on the board to lower its melting point.

it helps the wick suck it up like a sponge on water :) and prevents overheating nearby components.

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I have a "Katsu" rework station, with the a tip, and temperature regulation, as can be seen in the link below, however, after the information provided i found that the tips is not giving the displayed temperature (380º), on the point of the tip, but closer to the heat source, the temperature is closer to the displayed temperature.

I have a question, you would suggest to just get the tip, from Hakko brand, and that should be enough, or do you have any knowledge, about my rework station "Katsu", and you would advise me to get a "Hakko Soldering Station"?

Thanks in advance.

https://www.amazon.co.uk/Soldering-Heati...

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I linked the Hakko tip as an example of tip shape. You cannot use Hakko tips on a non-Hakko station.

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Hi, I´ve gone to a store to buy a Hakko Station, but the seller advise me to buy a JBC station (http://www.jbctools.com/ ). The price is relatively different with the JBC being a lot more expensive.

In your opinion do you think that the JBC Station, worth the value, and is needed to archive the work with tristar IC, or the Hakko Station will be more than enough, to do the job?

Thanks in advance.

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JBC stations are generally "higher-end" than Hakko stations but depending on which station you are looking at, you may not see the difference. I currently have the Hakko FM-203 with micro-tweezers. It's a great station but there are time I wish I had the JBC Nano Rework Station. However the cost difference is quite high so sometimes you have to pick our poison ;>).

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