Repair question

Started by gotw, May 06, 2015, 02:18:04 PM

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gotw

Quote from: Jdansti on May 31, 2015, 07:42:50 PM
Are you using a solder sucker?  If so, hover the tip of the sucker over the joint, heat the joint and then quickly place the sucker tip over the joint and press the button. Try to get the switch terminal up inside the sucker tip. It will take several iterations to remove all of the solder from each terminal.

That's what I'm doing. Glad to hear I might have the right technique. I'll keep working on it. Thanks!

greaser_au

#21
That is a double-sided (potentially multilayer), through-plated board, with very little hole clearance. Just looking at the photo I'd have to say you are going to really struggle with a solder pump like those - even using high-end desoldering gear here would be be a challenge. Faced with this just out of the box, I'd definitely have considered carefully destroying the switch from the top to save the board (I did this kind of work for a living for several years), but looking at the state of the board now, it may already be too late. It looks to me that the solder on most of the terminals is 'dead' (most of the tin oxidised or boiled off), so an application of fresh 60/40 solder is probably your best bet,  with John's (jdansti) advice. 

If you were able to heat all pins evenly at once with fresh solder  you might have a chance of removing the switch in one piece, but i'd imagine at least some of the platethrus will come out with it (sad experience talking)...

Also, is the anode of that diode at extreme bottom right (component side)  not soldered?

good luck,
david

gotw

Quote from: greaser_au on June 01, 2015, 07:47:37 AM
That is a double-sided (potentially multilayer), through-plated board, with very little hole clearance. Just looking at the photo I'd have to say you are going to really struggle with a solder pump like those - even using high-end desoldering gear here would be be a challenge. Faced with this just out of the box, I'd definitely have considered carefully destroying the switch from the top to save the board (I did this kind of work for a living for several years), but looking at the state of the board now, it may already be too late.

How do you destroy a switch from the top?

Quote from: greaser_au on June 01, 2015, 07:47:37 AM
Also, is the anode of that diode at extreme bottom right (component side)  not soldered?

Are you talking about the second picture? Good catch. I don't know. I will check tonight. Thanks!

tonight, we ride

Removing any component that has more than two leads can be tricky when you're learning to solder.

When taking your time and going slow is still not doing the trick, you can always cheat and use some of this stuff: http://www.chipquik.com/store/


Jdansti

Can you get some snips between the switch and board and nibble away at the terminals without damaging the board?

Otherwise, you might be able to dismantle the switch and then cut away at the base of it from the top, but the little tabs that hold it together might be folded underneath making them inaccessible.
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greaser_au

#25
Quote from: gotw on June 01, 2015, 10:18:58 AM
How do you destroy a switch from the top?

Dismantle/cut/break  the switch up so you can remove parts of it, leaving just the pins soldered into the board, then you remove them one by one.

Quote from: gotw on June 01, 2015, 10:18:58 AM
Are you talking about the second picture? Good catch. I don't know. I will check tonight. Thanks!

yes, second picture.  it looks unsoldered in all 3 though!

david