Info on T2-301 model FC-301/D

I did a search and did not get any info back. Maybe I am not searching correctly or maybe my equipment to to old!
All of sudden it does not work. I was wondering how to test it on the bench.
I have the GPS unit attached and it lights up. The unit itself has the Led power light on but I do not see any tx led going on!
How can I test it sto verify that it transmits?
Denis ve6aq