sundance-communications.com/forum Forums TDM Business Telephone Systems Toshiba Telephones & Systems Problem with GCO key on all phones

All phones are programmed with a "GCO" key, that is dead, LED does not even lite up....Group number 3/index 1. All programing seems to be correct. I reset PCB. If I changed the index number, I get dial tone. All call are made on PRI circuit. Thanks in advance for your assistance.

A few questions:
Did you assign the GCO index to the OLG and ILG?
Are you using GCO index in the DID programming instead of ILG?
About how many phones do you have and how many buttons on each phone?
What kind of processor do you have? For a CIX 670 do you have the extended processor or just the one processor?

You could have too many GCO keys programmed in the system. It is very easy to hit the max capacity.

System is CTX 100 with at least 20 phones (all 3200 sets, except for a couple of newer models). All the GCO keys were working just fine, until a couple of weeks ago. The only one that has quit working is the 1st one, as mentioned above, which was assigned as Index 1. I changed the index number to 12 on all phones, which seems to have fixed the problem. There is 11 GCO keys assigned on all phones, but actually only using the first 4. I did not do any of the original programming, I just do routine service on system, as needed.
The GCO keys are part of both IGL & OGL....number 3. I'm assuming that the index number assignment is similar to a line number, to make an line appearance on telephone.

The max number of GCO keys in a system for a CIX 100 is 64. I found out that when you exceed this limit that odd things happen. Sometimes it works ok for a while, then buttons stop lighting up.

When you could up 20 phones with 11 GCO keys, you get 220 GCO keys. If the problem returns I would start by reducing the number of GCO keys on each phone.

I have had GCO keys some systems work fine at some locations and have odd problems at others. For the problem sites we talked them into removing the GCO keys and just using multiple intercom keys and the Park key. Some people are very reluctant to change.