that may be the cure. not usually. locked out is usually the far end. if this one comes back. check the fax software. some fax machines disconnect time is adjusted bad. the disconnect looks like a "hold" flash or transfer. so after an outbound fax the machine holds the line, it times out and goes into lockout.
if you take any analog off hook long enough they time out and go into lockout. it could be the port but short is a very rare internal problem.. they tend to go open, or the relay gets "soft", sounds like a motor click-click-click, very fast
john poole
bellsouth business
columbia,sc