Hot air soldering anyone?

[gerrymoore]

I decided to put a new battery in my Samsung S21 All went well until I switched it on !! No fingerprint sensor... but everything else was working fine. So I took it apart again, made sure all the tiny connectors were clicked into place ..turned back on and Hurrah fingerprint sensor working

Put it on charge and went to bed a happy bunny. Next morning tried to switch the phone on and ...nothing, no screen, nothing. Stripped it down again and found I had damaged one tiny pin of the video output socket. This has 48 pins and is tiny ..I mean really tiny. So looked on youtube and it can be replaced ..the new socket is less than a fiver .... but you need a microscope and hot air soldering kit. Not sure if this is something I can do myself but I can't seem to find anyone who can.

So ..can anyone here help me, for lots of beer tokens, or give me advice on either who could do it, or who has done it with success?? Thanks in advance of some good news ....

 

[Guineafowl]

I do it with one of those cheapo hot air rework stations and a mag lamp. Put some flux on and play the heat around, gripping the thing with fine forceps till it lifts. Don’t pull at it or the pads might rip. Once off, some more flux and solder wick to tidy up the pads, then wipe over with a blob of solder on a normal iron to tin.

Fitting the new component is similar - I usually play the air back and forth a bit till the component slides about, then it self-aligns with the pads.

I recommend you find a scrap board to practice on first.

 

[JOEPRO]

Presume something like this if it helps or search on gaztube

 

[pint]

I 2nd everything guineafowl said

I did a surface mount chip on an hdd, wasn't super tiny but still fiddly. need to control your breathing like an olympic shooter

 

[sako243]

@gerrymoore define really tiny. My definition probably varies somewhat from yours. Do you have pictures of it or can find a picture to show me what you mean?

I don't really like doing repairs for people but it's something I probably have the skills and equipment to do.

 

[JOEPRO]

Might also be worth a call to local phone repair places and see do they mind you bringing it in stripped down ready for the solder repair.

 

[gerrymoore]

Hi guys ..I did go to the local 'phone repairer' he said it would be the screen and minimum charge would start at £200 ..I explained there was a broken pin ..I think he was deaf .....

Sako I've attached a photo .... you can just make out that pin 8 is partly missing but obviously that's the problem. The socket is 12mm in length ... I think this is tiny ?? I am in the process of trying to get all the info off my phone using a usb to HDMI monitor and a separate keyboard but waiting on these to arrive. I found a guy on youtube who has done this on phones that have no display ... If I can get all my stuff back and on to my spare phone then I would like to get it repaired. Is this something you could attempt?? If so, please pm me with a rough cost ...if not successful then I will still have all my important stuff backed up. Thanks Gerry

 

[sako243]

Got to run on the school run but see if you can have a proper look at that pin - I'm not convince it's broken and it's simply been deformed (pushed down into the receptacle).

If you've got a microscope and a scalpel (in my experience tweezers etc., won't be sharp enough - even the bastardly expensive ones I buy) you might be able to tweak the pin back up. I wouldn't worry too much about making it the right shape - just make it stick up enough. If it twists slightly that's okay - focus on getting it up first and then poke it sideways to re-align it. The mating half of the connector as it pushes down should push it more or less back into shape.

Might be enough for it to make contact. I'll get let you know later on today about possibilities of repair.

 

[gerrymoore]

Thanks for that ..I'll have a go and see what I can do ...

 

[gerrymoore]

Well I've had a go Sako ..only got a 40X jewellers loupe and a scalpel but couldn't keep it still enough or see enough to try and get at the pin. I'll wait for the bits I need to transfer all my data and then get back in touch ... probably be next week now but thanks for the help and advice so far ....

 

[David_W]

Might be a bit late, but to echo advice above, lots of flux, especially at that size. Small diameter solder helps, but with surface tension it's difficult to supply a small enough amount of solder if you feed the solder wire in, so instead add it to the iron tip and then just touch it to the pin.
Don't worry if you get too much on, sometimes when you get down to 0.5mm pitch it's easier to err on the side of flooding and then wick the excess off with solder wick, leaves a neat joint