sundance-communications.com/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.