Soundesign Clock radio with dead clock display segments
 

Hello everyone, yesterday afternoon (Sept. 30) I had picked up at a local flea market a 1970s vintage Soundesign AM/FM Clock Radio and when I got it home to test it out I noticed the red LED clock display has several dead segments which I have not seen anything like that before on an LED Clock Display before.

I am wondering if that might be caused by some bad capacitors or resistors or both on the clock's driver board?

Is this something that any of you guys on here have encountered before? If so how common is this issue, usually I've ran into issues where either the display works or the display is completely dead but never where the display is partially working (has some dead segments.)
The model number of the unit in question is Model 3643, which with a search of google nothing comes up, which tells me that it must not of been a very popular model. I have the unit torn down currently other wise I would of posted a picture of the unit.

I appreciate your help.

Is possible to have open LED segments. I have ssen it before (yes, is uncommon). Unfortunately, if is not a bad external soldering, solution is sub it.
Good is to have a "strong" multimeter with plenty of current at diode scale, so you can "sweep" the meter at display terminals; is good to have schematic or know the display, to avoid endless combinations for measuring.

Eventually, the IC driver have some damage, but then same segments at all numbers are off at same time (if multiplexed, like 99% of commercial clocks).

Finally, some clocks have a IC internally to a complete display, so, in this case, only subbing it to solve...

I have Sams Photofact set number 1885, folder 4, which covers model 3643C.There appears to be no components connected between the clock IC and the display. Resistors and caps are used in the settings and dimmer circuits.The diagram does show between minus 2 and 3 volts going to each display unit pin. Sorry, I can no longer post pictures here.

.

I remember those clock radios - My shop contracted with Yorx & LLoyds,
and we use to get skids of these things in under warranty. Very common was a bad
clock chip, or bad solder connections. A lot of the bad connections were on the clock
board. And of the clock problems were the long ribbon type flex thing that ran to the
display. We did not see many bad displays. You have to turn it on with the clock
in your hand, & flex it in your hand - that will most likely show you if it's bad
connections. If you think you have a bad display you can jump one display
segment to another just to test. If I remember right, those clock chips
did not multiplex the digets.

I also have to say that while Soundesign was no Panasonic, they did
make pretty good stuff back in the 70's I had a few of their radios
& they were much better than Yorx & LLoyds.

.

No kidding. Add to that Tops & Juliette. Hated that stuff. Carefully engineered
to be unrepairable ! Battery holder, antenna, thats the limit. SD was a step up !

73 Zeno:smoke:
LFOD !

An update on this clock radio, I did get the display fixed, it was bad solder connections on the clock display's ribbon cable going to the clock driver board.
:thmbsp: