I recently bought a Nitsuko 92030 card to replace one in my PABX that had a power surge (lightning). I am having some trouble configuring it to my system and think the problem could be with the impedance. How can I find out what impedance the card was set for and whether it is possible to change this?

My problem is that although the gate release now works, I get a screeching sound (feedback?) when I try and use the phone.

Bernard
South Africa

Forget impedance. There's no adjustment for that.if you swapped one card for another and they are set up identical you should be good. You say it was hit by lightning. How can you be sure other components were not affected? Namely door phone, power supply or CPU.

Dear Ron,

All good comments, for which I thank you. When I take out the door card, the PABX works perfectly, but when I insert the new (replacement) door card, the door opens but I get bad feedback on the line. Any other suggestions? I can't see any switches where I can set up the card.

Have you tried hooking the doorbox up at the MDF ?