atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems green stuff on 400D line cards

Hey guys, long time no post.
I happened to be checking some wiring and discovered green stuff inside my shoebox KSU coming from 2 of my line cards. Any idea what happened? Anyone want to sell me a couple new (old) cards?



Thanks!

Hi Jeff,

I have seen then before on some Ebay listings for 1A2. My guess could be something on the card opened up and started to leak the goo out.

But check this out on classicrotaryphones.com

http://www.classicrotaryphones.com/forum/index.php?topic=20852.msg213382#msg213382


But the experts would know for sure as I am not in anyway a electronics expert.

Brian

I also wonder if its some kind of glue.... But I could be completely wrong. I think I might have a old card with the same green goo.. I have to check.

Jeff - PM me.

Sam

Sam,


Do you know what that green goo is?

Leaks from the capacitors?

Sam

Exactly the same place on both boards which is evidence it's coming from something on the board. That yellow cap looks suspicious but I don't think there is any goo inside of it. Besides, it's coming from the transistor location and the front also.

Take a real good look and see if you can trace it to something.

-Hal

I have a few ksu’s sitting on the floor in my basement. A while back I went to move one and found it stuck to the floor. The cover of the 551b was open with the green goo all over the card cage and out the bottom cable opening. I first thought that something had leaked onto the KSU through the ceiling. Then I examined the power supply to see if the electrolytic capacitor had leaked. Checking the line card( 400D issue 14), it seemed that the goo was coming out from under the 327A reed relay( 3rd quarter,1972,Kearny). I pried the relay off the line card and found that the potting compound had completely liquified and leaked out of the relay. This is really strange since none of the other dozens of line cards I have has done this.
This is where the old Bell System is sorely missed. Bell Laboratories would have launched an investigation into the mystery of the liquefying potting compound and found the answer.
I don’t know if you guys have ever seen copies of the old “ Bell System Technical Journal”. Most of the articles are incomprehensible except to engineers and physicists, but every so often there was an article that a layman could halfway understand. An article in 1953 detailed the unexpected failure of relay contacts. An unknown organic compound was growing on palladium contacts. This organic compound eventually insulated the contacts causing failures. After going through explanations about palladium contacts, #1 and #2 Bell System contact metal and much scientific testing, it was determined that the source of organic compound was a chemical being outgassed from the relay spoolhead insulators. The solution found was to goldflash all contacts on wirespring relays and all palladium contacts. The organic compound was found not grow on gold. After all the testing and research the article ended on page 40 with” the exact mechanism of how the organic compound grows on palladium contacts is not understood at this time”.

There goes my theory that it was Soylent Green.

Ugly1 has identified the culprit relay, AFAIK.

This came up before, more than once. A while back, I cooked up a theory that something was causing the green conformal coating on the board to liquify... a long-winded spiel involving the mysterious syndrome known as "plasticizer migration."

Some time later, a respected source [meaning a guy on another forum who always seems to known his sh**] mentioned the green goop issue and said there may even be a BSP about it. The leaky relay was said to be the culprit, if my memory is to be trusted. [This was years ago.]

Paging Mr. Bloom...


Jim
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Speaking from a secure undisclosed location.