Saving my Mac SE/30. My first foray into SMD work

Tothwolf tothwolf at
Mon Apr 27 01:22:55 CDT 2015

On Mon, 27 Apr 2015, TeoZ wrote:

> You can do capacitor repair easily enough with just a soldering iron. I 
> have reworked dozens of mac and PC motherboards over the years (and a 
> few video cards).
> I suspect real hard SMD work (video chips and southbridges) might be 
> popular down the road to collectors.

Seconded. I don't own a hot air system (yet) and I do plenty of SMD work, 
including 0402 stuff and sometimes smaller. The single most important 
thing to have is liquid flux such as flux pen. You also really want a wide 
tip (chisel, knife, or hoof) on the soldering iron to carry molten solder 
to the joint. This is totally different from through-hole work since you 
are applying flux directly to the joint before applying solder. With 
enough flux, the right amount of solder just wicks right into the joint 
(yes, really!). Even fine pitch QFPs don't give me any trouble.

The only thing I've yet to touch are BGA packages, and I'm really not 
looking forward to the day when I have to...

Still...I see a lot of people using SMD tantalum parts to replace SMD 
aluminum electrolytics, and after seeing so many of these SMD tantalums 
burned to a crisp after they developed internal shorts, I certainly 
wouldn't use them for general purpose bypass work. SMD solid polymers 
which do not exhibit that type of failure mode are readily available in 
the same case sizes (round cans) as the original aluminum electrolytics 
and are also available in the same case sizes as SMD tantalums. Not only 
that, but solid polymers are less expensive than tantalum parts.

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