Hi I hope someone can help

Kxtd1232 master cab
2x 8 extn modules
1x pri isdn module

Slave cab
Is using 15 extns

My customer has a 1232 master and slave cab system. All extensions (more noticeable on analogue) have a background whine.
I have changed the master cab and cards but still have the same problem. If I disconnect any cards on the system the noise goes away, as soon as you connect it comes back!
If I disconnect the slave cab it makes no difference.

Can someone please help I am stuck!!!

Jim

So if disconnect the PRI card the noise goes away? If you reconnect that it comes back? But if you disconnect one of the extn modules it goes away as well?

Probably a bad main cabinet. We just replaced a main cabinet that had the same type of noise. Replacing it fixed it. Panasonic used to make their products last for a long time, but not forever.

It could be picking up noise from external source
try disconnecting one module at a time and then each extension on that module