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Recently I decided to invest in a rework station (namely the Yihua 858D) as I am sick of ruining pads when desoldering components.

Just today, I have fried £50 in components.

I am using the station to remove switches, jacks, USB connectors, etc. from a Bluetooth transmitter PCB, in an effort to slim it down for a project. I don't know how I am supposed to keep the solder molten, remove the component and regulate the temperature of the PCB so that the rest of the components on the board don't suffer. I am using the smallest nozzle, and have used temperatures in the ranges between 250-350 degrees Celsius, all to no avail. The board is around 5x5 cm, so it heats up quite fast despite my efforts (so much so that I can't touch it - is this normal?)

I have watched many YouTube videos, and have followed advice given to me (heat around the component, high temperature to avoid heating the PCB and only heating the component, circular motions).

What could be causing the failure of my parts? How do I use a rework station properly to preven the failure of parts?

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    \$\begingroup\$ You 've described everything except what you've destroyed and how you know it's destroyed. \$\endgroup\$ – brhans Oct 4 '20 at 2:16
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    \$\begingroup\$ Who upvoted this question so utterly missing critical detail??????????? Your abuse of the voting buttons is doing a severe dis-service, not only to this, site, but to the asker who cannot receive any meaningful assistance with their goal until they clairfy \$\endgroup\$ – Chris Stratton Oct 4 '20 at 2:55
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    \$\begingroup\$ @brhans I am working with the taotronics Bluetooth transmitter, which has a Qualcomm CSR8675 for the Bluetooth. I am not sure what exactly is being ruined on the board, and the reason I know it is being destroyed is because I tested it before and after desoldering something simple like a headphone jack, and afterwards the board either exhibits strange behaviours or does not function at all. My expertise is limited when diagnosing which exact components have been destroyed. Apologies for my vagueness. \$\endgroup\$ – brazed_blotch Oct 4 '20 at 9:33
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    \$\begingroup\$ @VoltageSpike the real question is why you closed this, and then improperly re-opened with the critical details still missing. The question is unanswerable. Erasing other user's quite proper close votes by such misuse of your powers is quite detrimental to the proper functioning of a site, where by design unanswerable questions are supposed to be closed, and say closed until details which could make them answerable are provided. We still have no identification of any specific failure or failed component. Thus only guesses can be posted, and guessing is not the mission here. \$\endgroup\$ – Chris Stratton Oct 4 '20 at 21:48
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    \$\begingroup\$ @VoltageSpike swapping the words around doesn't change the fact there there's still no identification of a failure or failed component. We literally have no idea what is wrong and so cannot help the asker. The idea that they damaged something by "cooking" it is fairly dubious. \$\endgroup\$ – Chris Stratton Oct 4 '20 at 22:15
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People use KAPTON TAPE for protecting components from the heat that we don't want to remove or repair.

Use resin flux to avoid the burning of tracks. Keep airflow medium and temp around 250degC. enter image description here

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  • \$\begingroup\$ Thanks for your answer. \$\endgroup\$ – brazed_blotch Oct 4 '20 at 11:04
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    \$\begingroup\$ @Deepak - Hi, Are those your own photos? As required by this site rule, when we include something in an answer (e.g. photo, image or text) which isn't our own original work, we need to properly reference (cite) it. If those photos came from somewhere else, can you please edit your answer and add a link back to the original web page for each of them, in order to comply with that site rule? If they are your own photos, I recommend adding a small self-citation below them. Thanks. :-) \$\endgroup\$ – SamGibson Oct 4 '20 at 13:20
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    \$\begingroup\$ @Deepak - "those are photos on my laptop for a long time, I don't know the exact source". If you don't know the source of the photos (and you didn't take them) then they are not yours & you can't self-cite them. Beware that copying non-original text / photos / images into answers here, can be treated as plagiarism. Since you don't know the source of the photos, I strongly recommend that you don't mislead people by that self-citation, and instead label them as "source unknown" or similar. At least that way, it is clear to readers that you are not trying to claim them as your own photos. \$\endgroup\$ – SamGibson Oct 4 '20 at 13:29
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    \$\begingroup\$ @DeepakPansari - You said: "Doesn't matter its mine or not. you people are making things complicated!" It does matter if you include photos that aren't yours without making that clear. Please read the site rule I linked earlier. If you want to stay on this site, please follow the site rules, even if you think the rules are "making things complicated". Or you can post on the Meta.EE site and try to get the rules changed. I do not accept that I am making things complicated. \$\endgroup\$ – SamGibson Oct 4 '20 at 14:00
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    \$\begingroup\$ @mguima - Hi, My comments to Deepak are only related to following the site rules. I don't want to expand my comments here beyond that. None of the suggestions you made are listed in the site rules, so I do not believe that those actions you mentioned (e.g. deliberate blurring of IC markings in photos) are required. If you have a different opinion, please raise it on the Meta.EE site for discussion. Thanks :-) \$\endgroup\$ – SamGibson Oct 4 '20 at 23:34
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I am using the station to remove switches, jacks, usb connectors, etc. from a bluetooth transmitter PCB, in an effort to slim it down for a project. I don't know how I am supposed to keep the solder molten, remove the component and regulate the temperature of the PCB so that the rest of the components on the board don't suffer. I am using the smallest nozzle, and have used temperatures in the ranges between 250-350 degrees celsius, all to no avail. The board is around 5x5 cm, so it heats up quite fast despite my efforts (so much so that I can't touch it - is this normal?)

If the components that you want to keep in the board are beeing blowed out from the board, I'm sure that you will agree with me that there are two concurrent reasons: the solder of those components is melting, AND the blow over them is too strong.

Sometimes, it's possible to use aluminum adhesive tapes, or kapton tapes, for protecting the solder of the components that should not be dessoldered.

But, many times, it is impraticable keep the solder of the components that will stay on the board from melting. In this situation, the way is to reduce the blow over those components, in order that, even if their solder melts, or soften, those components stay in their place.

If you want to dessolder only some of the components, but all of them are being blowed out from the board, probably you are approaching the nozzle too much to the board; keep the blower away, but, pointing to the board. It will take more time for the board heat up. Let the board and the components heat slowly.

Don't take the use of the smaller nozzle so seriously. Try with bigger nozzles; If the nozzle is smaller, their blow is stronger (and you don't want a strong blow that wipes everything from your board).

Gently blow the hot air to the board, slowly, until the solder melts; then you take that undesired components out, with a tweezer. If the blower is at a correct distance, the components that you will keep in the board will not change their position.

Practice with scrap electronics. If you have a multimeter with a bi-metalic thermo pair (for temperature measuring), put the sensor at the board (this is a very good learning practice), managing the slow heating of the board untill the melting point of the solder.

It is absolutely normal that you will not be able to touch the board. But you are not trying to hold the board with your bare hands, are you? The board has to be fixed to a support for this procedure.

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