DIYbanter - View Single Post

lid (Baytekk) wrote in
:

Thanks Andreas,

My frustration selected the word "scrap", my apologies, I would never
scrap these old DM44s I may "salvage" them, but only after I try one
last time to search-out & eradicate these resistance phantoms.

Thanks for the reminder on cleaning out the dirt, absolutely a must do
every time you "crack open" a new acquisition. I wish that was the
solution in this instance. I have a shelf full of specialized
chemicals & brushes for this.

The info from your chemist contact helps tremendously, sulfur &
chlorine compounds can be conductive and they can migrate through
certain mediums, like corrosion beginning at a battery terminal.
I looks like this type of contamination is initially very localized
and undetectable in QC yet migratory, and its only a matter of time
before it migrates through the board composite until it contacts a
couple of traces. This migration may take 20 years before it becomes
a problem from what I'm gathering here.

I have a few old Teks (a 453, four 465s, a 475 & the cadillac 485)
that are in beautiful condition. One 465 has one of my DM44s, the
thing is, is that this 465 has serial number B320864, this is near
the end of the production run for the 465 and I really want to keep
it as it was optioned (with the DM44). I could go on eBay & find
another "as is" 465/DM44 and swap out the boards, but I (as most
techs) would feel defeated by taking this route to solve a problem.
Yea, its personal. In the corporate world I would simply frizbee this
problem board.

My last ditch effort will be to unsolder all the components in that
area and begin ghostbusting. I did meet Bill Murray once a long time
ago at a party. LOL

Thanks again, Mike

Before you begin unsoldering,run the PCB thru your automatic dishwasher
with Calgonite,and then put in a heated (120-140degF) drying box for a few
days.

--
Jim Yanik
jyanik
at
kua.net