I just acquired a GMX-48..upon hooking up a phone on the display I get "SYSTEM LOCKOUT" ...and sure enough..cannot access any features...no intercom..etc. I reset/ initialized. ....no change. Any suggestions??? PS. Nothing on the main PCB ..SYSTEM LOCKOUT on two expansion boards.
Just making sure you know this is a 3 pair system with the blue pair reversed.
Yes ... the phones run off three pairs..and I have the blue /tip/r. reversed. It turns out the phones I used on another GMX48 don't work on this one..they give "system lockout" -660.7600-phones. The phones that do work on it are the 662.3400..apparently different chips in the KSU's. However, I can't get any phones to "come up" on the main KSU 662.1000 still--ODD..the main KSU doesn't fire up phones but the expansion modules do!? -repair time...
Have you checked the fuse on the main board?
The fuse looked fine....but indeed after switching to different module discovered it was bad. Thanks Dr Comm.!
Sorry it took me so long to think of that.