[Coco] DE-0 Nano Successfully Programmed!

[Dave Philipsen]

Wow.  This is going to be a big job.  A lot of this also depends on what 
drill size was used on the holes for the headers on the circuit board.  
If you use a small drill size so that the header pins just barely fit 
(which is actually the preferred method) then it's harder to get all the 
solder out.  A sloppier fit of the pin in the hole actually aids the 
de-soldering process.  But here's another idea just to keep up your 
sleeve that I have had success with.

I have found it to be VERY difficult to de-solder devices like headers 
with many pins because you always have a pin or two that is stubborn and 
remains attached to its hole.  You think everything's good and then you 
try to pop the header out and it pulls a trace up from the board.  One 
solution lies in heating all of the pins simultaneously so that the 
solder on all of the pins is liquified at the same time.  It only works 
well if the other parts have not yet been soldered to the board or if 
there are not many parts near the headers.  Put the board in some sort 
of vice or support.  Gradually heat the solder side of the board with a 
hot air gun.  Use a channel-lock plier opened up to a wide bite to grip 
the header on the component side and when you think the solder is 
liquified gently rock the header out of its holes.  The thing you have 
to be careful with is that you don't overheat the FR4....just enough 
heat on the solder side to get the solder to melt and then quickly get 
the header out.  This DOES work but you should practice on something 
first.  Heat up some old junk circuit boards with the heat gun just to 
get a feel for when you've gone too far with the heat and it starts to 
char the FP4.  I know this sounds like a brute force method but once you 
get the hang of it it can be very effective.

Just an idea if you find that the de-soldering vacuum isn't cutting it.


Dave Philipsen




On 6/7/2015 8:11 AM, Steven Hirsch wrote:
> On Sat, 6 Jun 2015, William Mikrut wrote:
>
>> Have you considered copper braid desolder wick?
>
>> Was introduced to it at ITT ... It works waay better than vacuum
>> desoldering.   Cleans the connection too if you're careful.
>
> Yes, provided you can get to both sides of the board.  Unless I've 
> misunderstood something, Kip soldered male headers into the piggyback 
> board, so the plastic carrier would have to be crushed or smashed to 
> get it out of the way on the bottom.  That's theoretically possible, 
> but sometimes the force involved causes damage of its own.
>
> There's a time and place for both methods, but I think the vacuum 
> desoldering rig is most appropriate for the first pass on a large 
> number of pins and has the highest liklihood of clearing out solder on 
> the far side.  Then, use some flux and fine solder-wick to clear any 
> stubborn remnants.
>
>
>