There is a new (vintage) addition to my shack - Kenwood TM401B. TM-401B is a 440 MHz Amateur Radio rig. As soon as I got it, I soldered the power-pole connectors so that it can be powered up in my shack.
I gave it a 12V power and I got no display!! I thought that it is dead, but after connecting an external speaker and reducing the squelch, I got white noise. Audio finally!! I tried to reseat the display board connectors but no help!!
I Measured the backup battery voltage and it was 0.11V :-( concluded that the backup battery (BR2032) was dead! Fortunately I had a few with me. I soldered one in place, after removing the dead one. Still no display!! I opened the bottom cover and tried to reseat the display board connectors but still no display :-(
I opened the bottom cover and and found a reset switch. I depressed it and voila! there was the display 0.000 MHZ :-0. I tuned the rig to an ongoing QSO and the rig was receiving well!
Don't know whether it is transmitting or not but so far receiving well! Let's hope for good.