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551B KSU not ringing

Started by Hill Haven Telephone Company, April 29, 2019, 01:04:21 PM

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Hill Haven Telephone Company

Ive got my 1A2 551B KSU all connected up to the definity. 

Everything works but the darn audible,  It was working just fine when I had it on the bench a few months back before the definity was installed.

Here is what is working

I can dial the KSU from the definity,  line button light flashes and comes on,  just no audible ringer
I can put calls on hold the hold button flashes.

I just dont know what else im missing
400D line cards in the KSU,  everything is grounded properly. 

Any Ideas guys?


I'm guessing you have a 118A generator installed.
Are the output from the generator connected to the RG, RB terminals on the lower right of the block in the unit?
What cards are you using? If your using D cards is your system earthed (grounded).
Have you removed any factory straps from the block?
Does the motor start when an incoming ring is detected.
Those are some basic questions needed to help troubleshoot your problem.


Hill Haven Telephone Company

Nope havent removed anything factory,  118A generator installed,  Its connected properly,  400D line cards,  and its grounded

Motor starts and light flashes when an incoming ring is detected.


Is the ringer connected properly in the telephone set?
Have you tried another card?
Have you checked for ring voltage on the block, to verify that you're getting the proper voltage outputed to the block.
Is the station cable connected to the system block.

It could be as simple as a bad cap on the network, mostlikey it's a miswired ringer. Or it could be the card isn't working correctly.

Hill Haven Telephone Company

Yup just tried different line cards,  there is ring voltage on the block,  the station cable is punched and good all the way to the system block.   Gonna try hanging it off my panasonic 616 and see what happens next. 


The only thing I can think of, is that the bell is connected correct, and does the cap on the network work as it should.
I don't know if you have other phones also connected to the system.

It sounds like the input of ringing is working fine, if it's operating lights, etc. Just doesn't ring with an incoming call.

Also if you're system isn't actually grounded using a wire from ground to the ground screw, but only relying on the power ground, the card will not operate on incoming calls, for ring,. I had the same problem when I used D cards and relied on the system ground. I had to run a separate ground for the ring to operate.


which phones are you using? just remember that the 560 and the 2560 series phones had the ringers connected to the RR and the RT terminals inside the phones. Any other phones I don't know about. but, on these phones you have to jumper the the line to the rr and rt connections, or the phones won't ring!


Good point John, but I assuming he's using the correct phone's. But I agree that the ringer isn't correctly connected, or there's an issue with the ground or cards he got.
I never liked using the D cards, I actually preferred the G card's, or the H.

Hill Haven Telephone Company

I think what im gonna do is find some G or H cards.   It would be easier than running the D cards