bm625 signal turn on and off after 3-5 secs

[Tierr]

Boss pa help naman po sa bm625 ko nakailang palit nko ng mac pati frequency pero ung signal ko ganun pa rin, after power on the signal turns full then after 3-5 secs it gets 0 signal then turns full ulit ung signal. sinubukan ko na rin sa ibang location at sa ibang antenna same problem appears.
thanks in advance