I had a caller ID card fail on an exiting system (MICS 7.1 FC) I notice that there are several different part numbers on the caller ID cards .The customer has (8) Lines 2 cards The card that failed was a
NT7B75AAAE The card that was in the system and working in either slot was NT7B75AAAG

I replace the card that failed with a NT7B75AAAE and got the same results as the card that failed I tried 2 cards both getting the same results no dial tone /static I tested the cards prior and they appeared to work fine on my test bench

I had a 3rd card which seem older and heavier look like it had more parts on it (it was made in Canada) NNTM845512PF/NT5B41GB-93 and this card seemed to fix the problem

The software on the phone system is 7.1 FC

is there some compatibility issues with these caller ID Cards


Just wondering


Thanks

JD

I believe we have experienced issues with accepting ring voltage range/variation between some of the different revision of T/Cards, but it was quite some time ago and can't remember the specifics.