On Friday, December 16, 2016 at 6:29:52 PM UTC-5, amdx wrote:
On 12/16/2016 1:11 PM, wrote:
On Friday, December 16, 2016 at 12:07:12 PM UTC-5, N_Cook wrote:
Third time in as many months, usual PbF phantom problems, solder looks
fine but no wetting between eyelet and pin and grey (tinpest?) pin, even
after desoldring.

I will render an opinion here based on my experiences with conventional lead-containing solder of differing natures.

a) Non-Eutectic solders will solidify in a non-linear fashion as it cools.
b) My experience with 60/40 and 50/50 solders with wires is that the cooling is often based on the wire as it is a heat-sink.
c) Dynaco equipment uses a lot of eyelets set in circuit boards.
d) Using solders as described above, on more than one occasion I have gotten visually excellent connections that simply twirl in the eyelet, as the solder cooled (dumped heat into the wire) so fast that the shrinkage pulled it away from the eyelet before it was actually solid.

This is purely anecdotal.

Today, I use only truly eutectic solders on my electronics (37/63 lead/tin) - with a very few exceptions, when for one reason or another I need to use silver bearing solder. In those cases, I use 96/4 tin/silver, and great care not to move anything as it cools.

Peter Wieck
Melrose Park, PA


I had an eyelet problem 30 years ago on my Philips CD player.
I couldn't fix it, so I sent it to Philips Repair. I worked at an
authorized service center at the time.
The sent it back saying they could not fix it.
I mentioned it to a fellow tech and he said, "let me look at it".
He put a wire through each eyelet and soldered both sides.
That corrected the problem.
Mikek

Motorola had their "famous" Placir printed circuits in the 60s, and they were notorious for connection problems between the top and bottom layers. The only solution to permanently repair these was to hard wire the top to bottom.

GE in the 70s had a line of TVs that used double sided boards with hollow griplets crimped through the board and covered with a thin layer of solder, and these would develop a dozen or more gimpy connections. Flexing the main board would cause all sorts of color, sync, brightness, video, sound issues etc. Resoldering them was difficult because the boards would out-gas badly when the griplets were heated causing cold joints. Instead of hand wiring the 50 or more griplets, I solder one side thoroughly feeding in lots of solder, turn the board over and remove the excess solder that came through, resolder that side thoroughly, and turn it over again and reflow a third time. The outgassing usually stopped by the second pass. They never came back after that.