On Sep 22, 9:23*am, Jeff Liebermann wrote:
On Wed, 22 Sep 2010 05:05:19 +0000 (UTC), Sergey Kubushyn

wrote:
Jeffrey Angus wrote:
On 9/21/2010 11:29 PM, Sergey Kubushyn wrote:
I recently restored and fully recapped two Kenwood KA-9100 amps. All the
boards are phenolic and I used solder braid on them.

And they are not multi layer boards with 0.010" traces.

They are not. There is no such thing as _phenolic_ multi layer boards with
0.010" traces.

Not yet. *Some experiments in printed semiconductors and 3D circuits
use multilayer boards. *However they don't use solder. *They're
stapled together. *They're also intended to be throw away assemblies,
so I wouldn't worry about repair.

BTW, solder braid is very useful on _ANY_ board, including multilayer ones
with 0.010" traces. It requires some skills of course but everything does. I
do use it all the time.

I've been soldering for about 50 years, so I suspect I'm sufficiently
experienced to have made all the usual mistakes (several times). *It's
not the lack of skill. *I have no problem using braid on large objects
with small heat sinks. *I have nothing but problems using braid on
small objects attached to large heat sinks. *I this case, there's a
small leaded capacitor, connected to a rather large copper heat sink
of the power bus inside the PCB. *You can see the effect when
unsoldering the capacitor leads. *The ungrounded hot lead comes out
easily. *The grounded lead is far more difficult. *If the capacitors
are near the CPU and on a power bus, then both leads are difficult.
Braid is also quite suitable for unsolder connections where the solder
is easily accessible and exposed to the braid, such as large xformer
pins, terminal strips, wire terminals, some IC sockets, tube sockets,
etc. *


I noticed that one of the capacitor leads is connected to what looks
like a fat copper trace (ground?) The other lead seems soldered to
just a tiny little circle... if I hadn't looked closely, I might have
soldered it to ground by mistake too...



Also remember that this is for what appears to be a beginner at
repair. *It's easier to explain how to operate a solder sucker than
braid.


Yes I'm a beginner at this, and thanks!



I forgot to mention the desoldering bulb, another device that barely
works:
http://www.amazon.com/Weller-Desoldering-Bulb-Solder-Off/dp/B00011TUZY
The only good part is that it's great finger exercise (I play piano).


I heard that the bulb doesn't work very well. My dad has one. And
hey, I play the piano too! Trying to learn how to play George
Winston's piano solos... The Cradle is pretty straightforward, but, oh
man, his variations on the Carol of the Bells is extremely tough!

Michael