Wire behind where LCD plugs into the system board

[rattlehead]

There is a small wire that plugs into the system board of a T22. It is shown on page 113 of the HMM. Does anyne know what this wire is for? Mine is broken off on the one end of the system board and I am not what's not working. I am thinking that it's probably the lead for the modem or could be the serial port.