My recently purchased used m700pro was dead when I went to power
it up. it had a blown fuse , The 5 amp one inside. I replaced that and now it powers up. the display lights and flashed "tune"
I have set the config to no auto tuner
I have only a short wire connected to the pl259 antenna
connection, not a proper antenna
by any stretch, but thought I should be able to change freq and check receiver getting anything.