Advice on desoldering 2600 parts

[Evanlor]

I'm attempting to desolder some switches on a wonky 4-switch VCS and use them in another VCS with a broken switch or two. I'm have a heck of a time getting them off.

 

What i've done so far:

Used a solder pump to remove most of the solder.

Tried using braid to remove the rest but this does not seem to be working.

 

I've only just begun to solder in my life, so technique and hints are REALLY sought after.  Thanks!

David

[+batari]

1 hour ago, Evanlor said:

I'm attempting to desolder some switches on a wonky 4-switch VCS and use them in another VCS with a broken switch or two. I'm have a heck of a time getting them off.

 

What i've done so far:

Used a solder pump to remove most of the solder.

Tried using braid to remove the rest but this does not seem to be working.

 

I've only just begun to solder in my life, so technique and hints are REALLY sought after.  Thanks!

David

Does your braid have flux? If not use flux on it, as this helps a lot with the wicking action.

[Evanlor]

50 minutes ago, batari said:

Does your braid have flux? If not use flux on it, as this helps a lot with the wicking action.

I'll start with that, thanks.  I'm pretty sure it has no flux.  In addition, I'm holding the braid on the solder, then the iron on the braid.  Is that correct form?  Thanks again!  

D

[mimo]

Start by putting some new led solder on the old joints, also as advised add some flux.

 

[+fdr4prez]

If it is just the switches, and not heat sensitive components, then you can get a heat gun and blast all the pins at the same time with some hot air to melt the solder and then you can pull the switch off of the board.

[+Stephen Moss]

If the PCBs have plated through holes it can be difficult to remove the solder from both sides of the PCB and from within in hole using a simple de-solder pump, consequently what remains on the other side of the PCB/in the hole keeps the component attached to the PCB. I don't think the 2600 PCB's are plated through, at least not the early ones, if you can only see solder pads and tracks on one side of the PCB then it will not have plated through holes.

 

Most people repeatedly try to desolder a pin or leg if the first attempt is unsuccessful without first re-soldering it because doing so is counter intuitive, however if you removed 80-90% of the solder on the first attempt what resoldering does is connects all the remaining solder together so that the heat can reach and melt it all. Consequently, without adding solder only some of the remaining solder may get heated resulting in further failure, additionally the repeated heating in attempting to remove what solder remains can result in pads and track coming away from the PCB.

  

So if you have tried 3 unsuccessful attempts at desoldering a joint without resoldering then first try re-soldering the joints so that there is plenty of solder before attempting to desolder again.

Second, where most people go wrong with a desolder pump is having it too far away from the solder joint so that by the time it get there the solder is already resolidifying. Try keeping the desolder pump right at the joint at an angle of around 45 degree on the opposite side to where you are applying the soldering iron. Apply the soldering iron for 3 or 4 seconds to ensure the solder is fully melted, then in one quick and simultaneously movement remove the iron and, tilt the desolder pump over the joint, pressing the button when it is upright over the joint. 

You may want to practice your timing of this with a cold soldering iron first, as you want to be quick while avoiding the desolder pump nozzle from contacting the tip of the soldering iron. Hopefully that will allow you remove all the solder on your next attempt.

 

If the component appears to be free of solder but still attached to the PCB it may only be a weak link with tiny amount of solder, wiggling the component/component leg from side to side or back and fourth may crack the remaining solder thereby freeing the component, but in trying that you do risk breaking the link between the track and solder pad.   

[Bruce Tomlin]

On 4/29/2020 at 1:11 PM, fdr4prez said:

If it is just the switches, and not heat sensitive components, then you can get a heat gun and blast all the pins at the same time with some hot air to melt the solder and then you can pull the switch off of the board.

Note: unless you're using an SMD heat tool with a sufficiently small tip, be sure to put aluminum foil around the area you want heated to mask the heat from where you don't want it. Otherwise you will have a de-soldered switch mounted to a warped case.