atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems Burned Out!

Hello everyone, it's been a while since I've made a post in this forum. I hope everyone is doing well. A long time ago (with the gracious help of y'all), I set up and got my San Bar 1A2 KSU up and running. Since then, something has happened to it. It's been sitting in the closet for at least 8 months now, and I finally have sat down again to try and figure out what happened.



Thanks in advance everyone!

Pictures:

Line Card:


KSU:


66 Block:


YouTube Video:

Click here

Your problem may not be the interruptor but rather the power to run it. Both the lamps and the interruptor run on 10v AC.

You need to check the output of the power supply to see if it's putting out 10vac. I'm not familiar with the Sanbar KSU but it should have a spot whe you can check output voltages. 10v AC may be listed as LB (lamp battery).

Sam

Good idea! So I just use a voltage meter across the lamp leads?

No I think he said to check the output of the lamp 10 ac at the power supply.

What Jim said. Check all voltage outputs directly from the power supply.

If the supply follows conventional 1A2 standards then it should have:
10V AC ( for lamps and the interruptor motor)
-24V DC - filtered (A Battery, for intercoms)
-24 V DC - unfiltered (B Battery for relay operation)

There should be a place to measure them, either coming directly out of the power supply, or very possibly on one of the 66 blocks.

Sam

Sorry for the delay in my reply. I will look into this when I get a chance and I will post an update. Thanks for your help guys. Merry Christmas to you!

Update: I have finally figured out the problem, and it's worse than I thought. It turns out, I must have misunderstood how to connect single line telephones to my 1A2, so since I got it I have been using the A lead ports for my Tip and Ring. As far as I know, all of my system's components are in working condition still, but all my KTU's are done for good. I'm disappointed for sure, but KTU's seem to be readily available on eBay, and I'm sure at some point I can pick one up and get my system working again.

Shame on me for my ignorance! But I suppose I can call it a lesson learned the hard way.

Thanks for all the relentless help everyone on here always gives me!

If I understand you correctly:

Putting the T & R of a single-line set across the A + A1 leads should not have caused any damage to the line cards. Is that what you did? I suspect that you did something else if your KTU's are fried.

You would be advised to do some research and educate yourself first, before attaching wires to things. Do you have the practice (instruction sheet) for that KSU? If not, we can easily point you in the right direction on the web where you can learn about 1A2.

The line cards (400-type) are free, essentially. Don't pay more than a few bucks for them. I have a few I can send you for the postage.

Sorry for the delay, I've been quite busy the past few days.

To answer your question:

I did exactly what you stated. Since you say that this wouldn't cause any damage, I'm honestly not sure what happened to the line cards now. I may have crossed two wires somewhere and damaged something, but knowing that most 1A2's could survive just about anything makes me doubt it (although they aren't indestructible).

In response to your generous KTU offer:

At the moment, I'm quite satisfied with the Merlin, and with the amount of electricity I've been told by my parents that the 1A2 consumes, I don't think I'll be messing with it anytime soon (which is sad in a way).

I hope at some point, possibly during the summer, that I can fix it and get it running again. I sure do miss seeing those bright line keys!



Thanks for everyone's help once again.

You might want to clean up the termination block, start from the right side not the left, your white orange and yellow slate pairs are reversed and it looks like I can see bare wires as if you punch down tool didn't cut the wire, are you using a punch down or a screw driver?