My summer project begins.

[Key2871]

Ok, I need wisdom for this next problem.
I found a couple problems solved one by replacing the key because something was drawing power and making lights dim. So I just replaced the key for now, problem solved.
Next is odd, I have a 401B KTU when it's plugged in it immediately triggers on. I've checked and rechecked wiring and can not locate the issue.
I thought it might be the jumper strips installed, no.
I unplug the card and problem goes away.
Replace with a 400 G and it's fine.
It's only when I plug in the 401B intercom card that it triggers. And for the life of me can't understand why.
It works fine with any of my other sets, just that 830 that's giving me fits.

Anyone with experience more than I, can you give me ideas what the heck I need to look for?

I think I have a few loose leads that go to the terminal board are in the wrong places, I have found a couple tus far. But I just can't figure why that card is triggering?
Thanks in advance for the help.

[Babybearjs]

take some pictures! I did!

[Key2871]

Are these more parts? I don't understand why your posting pictures here..

[Key2871]

Ok, I've isolated the A lead control, I've pulled the plug from the key that operates the line the 401B is on, I've tried to figure out why it's triggering the card..
Nothing I did stopped the problem.
As soon as I unplug the set, it shuts off.

I've checked the wiring to the terminal board, etc nothing stops it?

I truly cannot figure this issue out?
It only effects the 401B nothing else, and the problem followes the card, no matter where it's plugged in.
But everything works as it should with that 832 un plugged.

Does anyone who's done 1A2 have any idea what the heck is causing this?

[Jim Stettler]

Could it be the intercom card ?
Do you have another 401B intercom card to try?
Just a guess,
Jim

[Key2871]

No that's the only one. And I've thought about that, but why just that phone?
It doesn't act up with any other phone.

I can't figure it out, it's driving me nutty.
I really don't have to use it, as I have the Valcom unit connected for my intercom. And I guess I'll keep moving forward, I don't want to get hung up with this card. If I figure it out may be I'll post the solution here.

[Jim Stettler]

No that's the only one. And I've thought about that, but why just that phone?
It doesn't act up with any other phone.

That makes it easy.
It is the phone.

I know nothing about key stuff.

But since it is only on the intercom card
and only on this set
then the problem is most likely at the electrical interconnection of this particular telephone to the intercom path.

Just my guess,
Jim

[Key2871]

Yes, but where. I've isolated as much as I can think of but it's still acting crazy.
Well like I said it's fine otherwise so I'll just have to figure it's out at some point.
Time to move on. Thanks anyway.

[Key2871]

Jim, looks as though your right, the card won't work anymore.. Oh well.

[5415551212]

The 401B intercom card is pretty simple card right? A relay and possibly a resistor?
I suspect a common ground issue.

[Key2871]

Yes it is simple, no resistor I can see. But a jumper on the board from one trace to another.
I'll delve into what is possibly wrong at some point.

Thing I'm still not understanding is why it would operate with no key pressed, just plug the phone in and it operated. I isolated everything that could possibly cause it but it made no difference.
Any other line card in any slot worked as it should, with the question phone and everything else.

[Jim Stettler]

I think a  replacement board shouldn't be hard to find at a reasonable price.
The switch folks hang out on TCI. The TCI Mattoon  IL Telephone show is mainly switch folks. They play with older stuff but I am sure some of them have some 'modern' Key stuff like you need.
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September 10-11, 2021
https://www.telephonecollectors.org/shows/2021/Mattoon/index.htm 

Babybearjs could probably get some info regarding early color code from the same folks.
http://www.classicrotaryphones.com/forum/index.php?topic=24770.msg249776#msg249776


I went to it in 2019. small show, mainly switchers. It was a lot of fun.
JMO,
Jim

[Key2871]

Thanks, but I really don't use it anyway, because I use a Valcom RT19 for intercom. I was just curious as to the schematic looked for the card, so I can easily understand what I'm looking at on the underside of the board.
If it's dead, it's dead so be it.

[5415551212]

Hey Ken how'd your summer project turn out? Any updates?

[Key2871]

Actually got very busy over the summer, and had some arthritis issues that kept me out of the shed, it was either Hot or cold and rainy.
But I've got plan B lined up hoping soon, setting up a portable table in the house and connect the KSU cable to the house, and I'll have my own setup inside where it's warm.

Because anyone with arthritis knows, cold gets in and tends to slow you down.

I've been kicking myself for a couple months and itching to get back to that again.

So with the holiday fast approaching, it might be a couple weeks, both my young boys will be home from school so I don't want to get involved until after they back on a M-F schedule. My 11 year old gets into stuff he shouldn't.

I didn't want to post this information before, in case I got side tracked again. But I am getting antsy to get back at it, just not in a freezing cold shed..
But when I get set up inside the house I'll post some info then. Hoping very soon..

Another thing, I haven't jumped into the 401B card at all.
But from what I've seen of the schematic I think a coil failed on the board relay that's why it's not working anymore.
So I'm probably better off with a newer card.
Because I'm sure finding a coil/ relay set up is not going to be easy or plausible for replacing.