atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems ITT 400E's Broken or Not?

Greetings all.

I've got four very old ITT 400E's in my 1A2 systems that are working fine. I wanted to get an extra or two to have around just in case.

I got several others to test out--two used and two brand new. But those four do not fully work. They will activate the line light when I pick up the line. But hey will not flash the the light when a call comes in, nor will they put the line on hold.

Having four working cards and four working slots to test these faulty ones, I'm certain the only thing it could be is the cards themselves. I've checked cards to see if their straps and jumpers are set up the same way as the working cards. As far as I can see, they are.

So here's my question. Anyone ever heard of this particular issue? Is it something that can be fixed by moving any of those straps/jumpers around, or does it really mean these things are doorstops?

Thanks much for your thoughts.

Bob Goodman

Doorstops. 400-type cards are plentiful, at around $5 each. Stay away from 400D from Western Electric, stamped earlier than Issue 15. SanBar 4000F are the most reliable, in my experience.

That's what I figured. Just wanted to be sure before I took them to electric waste recycling.

I wish they were a bit heavier. Then I could use them as paperweights.

Know anybody who might have a working ITT 400E?

I'll look......

Sam

I've actually got a couple. Lamps light online pickup. Wink on hold and Flash on incoming ring.

Sam

Cool. Can you part with one?

I can PM me with information.


Sam

You have pitted contacts on one of the relays. Easy fix if you want to pop the covers on them and use a very gentle burnishing action.

ITT 400E card is the best design of 400-type cards (which was as well admitted by Bell System/Western Electric based on several quality/trouble statistics done by operational compaties). I have 30 of ITT 400E cards in my possession and I have never come across a faulty one. SanBar 4000F I have as well and there are some faulty.

The design of ITT 400E card is based on single side PCB (which is much easier to repair vs. double sided). It only has basic discrete components - not like WE 400H with custom logic IC. Out of active components it has a single generic operational amplifier IC (8 pins) and 2 or 3 transistors. This should be very repairable.

I use WE 400H which has a single advantage of being silent (click-free) as there is only a single reed relay used in that, and ITT 400E which has an extra benefit of automatic release of abandoned incoming calls from hold behind my PBX. Abandoned outgoing calls still have to be released from hold manually.

If faulty - I would first check and replace the electrolyte capacitors, those are the most aging components especially when not charged for a long time. If this doesn't help I would replace the transistors. And if the issues is not with those - change the Op.Amp. IC. I am assuming that the relays are checked and contacts are clean.

Thanks much everyone for the ideas. And Happy new year.

Repairmen liked the clicking relays. They allowed the repairman to locate the correct card in an electrical closet that might have 100 or so in service. You asked the secretary to slowly operate the switch hook, until the correct one was found, by listening and feeling for the vibration. This was before the cards were equipped with LED's.

I really like the ITT 400E cards. I've only had a couple fail. Both times it was bad diodes. Nothing special, just your garden variety 1N400x type. I keep a bucket of 1N4007's around so I just swapped them with those. They work just ducky.

They don't have that stupid thing of some western electric cards where they only ring up on grounded ringing (like pre issue 15 400D's) or some of the wackyness of the later WECO 400 cards. I had some 400H's that if you quickly pressed the hold button and released it (LIKE ANYONE NORMALLY WOULD) it would drop the call. You had to keep the hold button depressed for a solid second or more to reliably hold the call. They've since been sitting on a shelf for 5 years. I like the issue 15 400D's. 5 of my 6 line cards are currently those. They work wonderfully. Someone at the Lancaster TCI show a couple years ago had a 1A2 rack with like 5 or 6 loaded 584 panels and I asked if he'd sell some of the line cards. He said sure, so I picked out all the Iss 15 400D's. I doubt I paid him more than a few dollars a piece for them.

400D cards allowed for common audible ringing without a ring generator. Yep, that's what I said.

Chris, the cards that you refer to actually needed the line to be engaged for a second or two, before you could them on HOLD. It wasn't a case of the length of time you held the button down I discovered that "feature" on the job, after throwing away a few before I figured it out.

I always thought this issue with the 400H cards wasn't an issue at all. I thought it was intentional to discourage people from placing lines on hold and tying up equipment in the CO/PBX.

I would agree. I saw it as an additional feature, e.g. allowing to drop accidentally picked up line (from unrestored button) just by hitting the hold as a button restoration. Apparently there is no need to place a bare dial tone (with no incoming call or any dialed number) on hold. 400H effectively prevents such “false hold” situation.

400H has another advantage of being more “solid state”, having only a single mercury wetted contacts reed relay. So it is “silent” in operation with no audible clicks like from other relay-based line cards. This is only an advantage when the KSU is placed in the same room as phones, not in a separate closet. One can still hear the interruptor running, but only when hold or ringing occurs.

A big disadvantage of 400H is its zero repairability due to several custom ICs used for handling the logic. So if the card is troublesome it can only be thrown away rather than repaired.

THIS IS A SECRET YOU MUST NOT KEEP

I'm going to try this right now, and if you're lying to me.....

Who am I kidding, I'll just whine some more and then get over it.

He was right....

However, they don't work with my 451B MOH card, so back on the shelf it goes.