BCD436HP/BCD536HP: 536 deaf? Could be the ribbon cable

[N9JIG]

Recently a friend of mine has a 536 suddenly go deaf on him. The display and keyboard operations worked normally but the radio was RF-deaf.

As he is much smarter than I (and has the appropriate test equipment) he traced back the antenna connector and found no issues into the RF section. He found some odd readings with an oscilloscope near the ribbon connector on the main board so pulled it and reseated it. The problem was solved! The radio is happily receiving as it had before.

I have had ribbon connector from the main board to the display/keyboard daughterboard separate on 996/BCT15 series radios before, these share the same basic internal layout as the 536. These usually manifested themselves with keyboard malfunctions or wonky displays but I haven't had RF deafness come up before. (See BCD996P2 3, 6 & 9 Buttons Not Working and other threads for that discussion)

If you have sudden RF deafness on a 536, 996 or 15 series scanner and are up to the task try reseating the ribbon cable and see if that fixes the issue, it might save a repair bill! Same goes if the keyboard stops working properly or the display acts up.

The dab of glop that Uniden uses to help retain the cable can dry up and shrink, which in turn can actually help pull the cable out from the connector slightly while not readily apparent visually. I usually use a dab of Elmer's Glue if I have that handy after reseating it on my radios.

 

[tvengr]

To add to your 536 experience, my friend had a BCD536HP which appeared to be totally dead: no display, no backlight, no receive, nothing. It was all caused by a bad SD card.

 

[gary123]

IIRC There was another post here about something similar. I believe the user said he reseated a connector (maybe with a brown wire on it). This brought the unit back to life. if you feel comfortable opening the scanner I would consider unplugging and re plugging in all the connectors and then retest the scanner. see if that fixes it.

 

[Ubbe]

I've had ribbon cable issues on several different scanner models but in all cases the ribbon cable are seated firmly as far as it goes. Sometimes I had to pry off the glue to be able to pull the cable and reseat it. In all cases that have solved the problem. I don't add any glue and haven't found any ribbon cable trying to creap out of its connector, but then I only use them on my desk and not in a vehicle where there could be vibrations.

It must be some type of oxidation of the contact surfaces. I still have one BCT15 where the display backlight goes out. After reseating its ribbon cable it works for a couple of weeks and then the light dies again. This repeats after each reseat of the cable. Maybe there's a crack in the ribbon cable or a bad solder joint to one of the pins of the connector. Or the high current to the backlight puts a bigger stress on the ribbons coal surfaces. I could probably solder a wire from the mainboards connector to the front panel connector between the pins that the backlight uses.

/Ubbe