atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems Troubleshooting help, please?

And are those 2 cables by any chance on the same block? IF so, change the block out when you repunch the cables. Wouldn't be the first time hidden corrosion or carbon tracks or stray clippings caused weird problems. And pitch the block! Never reuse a block that 'may have been bad but wasn't'. I never reuse a block, if I have a choice. That just increases the odds of a weird problem, like you've got! John C.

Yep, they are on the same block, and are directly across from each other - bridge clipped.

I'm pretty sure it's not the blocks, got 'em brand new from Ed.... but a stray wire clipping could be a culprit, although I gotta tell ya, I've been over this block at least 50 times over the past week and didn't see anything amiss.

be sure to do what justbill said, the violets are connected in the sets and used for speaker phone.they will cause strange problems; trust him.

Will do.

In the meantime.... I've taken a slightly different tack.

It's been about exactly one year since I started on this journey - over this time, I've learned alot, changed alot, had some time to take a look back and say... ya know, I really should have ...

And so.... I gutted the whole thing. Nary a punchdown is currently in place.

This is kinda like final exam time. Taking all I've learned, mistakes I've made, and seeing if I can do it all from scratch without asking any questions. Which isn't to say I won't refer back from time to time to some of my old posts.

But, I'm gonna take it slow. One keyset at a time. Verifying all functionality is clean after each one.

.... and away we go.......... goal for tonight is to just get one keyset back in operation.

Take off the bridging clips, for a start. That's what we mean by "make sure they're disconnected at the block."

Well ..... the winner is Ed & Bill. I got to the point in the "do-over" where it was time to punch down one of the two troublesome keysets. Did so, and the noise came back. Opened up the keyset, and someone had already snipped VIO/BRO and put a scotchlock on it. Also YEL/GRN - GRN/YEL were disconnected and just hanging there uninsulated.

I hate opening a keyset and finding a scotchlok.

I disconnected the pairs and the noise is clear.

Anyway, if anyone has the time, can you explain why the last 3 violet pairs cause these issues if they are teminated at the block, but not the keyset? Does it cause some sort of induction or something?

Thanks
Matt

The last three pairs (actually two and a half) are the leads used to permit remote control of the set by a 4A speakerphone system. Dial tone output from the key strip is on one of the pairs, so if this pair comes in contact with anything, it will cause problems.

And the bridge clips brought them in contact with? That's right, the phone across the block! I learned very early in my limited 1A2 experience that a full block of bridge clips 'all dressed and covered' (Old Air Force, and probably other services, expression) is pretty, AND likely to cause pretty mucho problemo, especially if you are scattering extra lines among the phones, or mixing 5, 10, 20, and 30 line phones in any combination. You ONLY bridge what is necessary on a 1A2 66 block! John C.

Yep - I just bridge down T, R, A, A1, L and LG for each keyset. And the ringer as well I suppose.

Speaking of which, all that's left to do is the intercom and ringers. Although Ed's suggestion did fix the problem, I was wanting to gut and redo it anyway. There were alot of benefits, but probably the biggest one is how I tied everything back to the CO block.

It's probably still not right, but it's 50% better than what it was.

I used to have every keyset daisy chained between 66 blocks. I did that because at the time I was more clueless than I am now, and didn't see any way to bring each 66 block back to the CO/KSU; there simply weren't enough terminals.

This time I fed the upper and lower rows of 66 blocks seperately to the CO block, and daisy chained from there. Again, I'm sure it's probably still not right... but it's better, or at least, easier to troubleshoot.

I also have been fiddling with it a lot over the past year, and didn't like the way I had originally punched down some of the keysets. Time for a housecleaning.

So, the problem could have been fixed in about 30 minutes instead of the 12-14 I spent, but it's a lot cleaner now.

Anyway, just wanted to say thanks to everyone for the help!!!!!!!!!!!

- Matt

"The last three pairs (actually two and a half) are the leads used to permit remote control of the set by a 4A speakerphone system."

And 3-type speakerphones, too.

I worked in a hospital that had over 12,000 key sets, and our rule was "always a home run, and never a bridging clip." I think there might have been 100 bridging clips in the entire hospital. They are the Devil's tool.