1970 Sony AM/FM Clock Radio Model TFM-C770W Issues

[vortalexfan]

Greetings everyone, I just acquired today a long sought after clock radio, A Sony Digimatic Clock Radio (the old flip-dial style clock radio), which I had been looking out for one of these for a long time, I actually had one for a while that I found at a local Goodwill store that was still a fully functioning unit (including the clock mechanism) but then the alarm mechanism started acting up (it would go off when it wasn't even set to go off) and so a friend of my old house mate told me he could fix it for me (that was before I had a lot of experience with working on solid state circuitry) but then I never heard back from my former house mate's friend ever again and never saw the clock radio ever again, so I had been on the lookout for another flip-dial clock, and I did finally find one today at an antique shop up in Niles, Michigan which is about 35 minutes northwest of me, and I got it for $30 (which is a bargain because for some reason there are some people on feebay who seem to think that these old Sony Digimatics are worth a ton of money and are trying to sell them for $300-$500.)

Anyways the one I acquired was one of those Blacklight models with the date, day and time readout, but unfortunately the motor was seized up on it and it uses an Omron made Telechron Style rotor to power the clock mechanism and I tried to see if I could free up the rotor but unfortunately the plastic gears inside the rotor module had warped over time and so now the rotor refuses to work period.

My question is, is there a source out there for a new rotor for these old Sony Digimatics and if so, where did you get them? If not, what kind of motor did you use or adapt to make the clock mechanism work again?

I did go to the Telechron enthusiasts website (telechronclock.com) and sent the guy there an email to see if he could rebuild the rotor in question since it is technically a Telechron rotor but was built by another company via liscensing rights from Telechron.

Thanks for your help.

See picture below to see what the clock radio in question looks like.

[vortalexfan]

Update: I got a reply back from the guy at the Telechron website and he said that while the rotor used in this clock is a Telechron Liscensed product its gearing inside is different enough from an actual Telechron Rotor that he couldn't rebuild it because the tooling he has is specifically for Telechron Rotors which have just enough of a difference between them and the rotors that were made by Omron for Sony using Telechron's Patent Liscense that he can't use his equipment to rebuild the Omron units.

I did find another Alarm Clock like this unit on feebay, that has the same issue (with the dead clock mechanism) that I'm going to try and see if I can attempt to free up the motor on that one using a little bit different method than I did before and see if I can avoid screwing up the gears inside like I did on the original one, and just use the other one for parts, such as the clock mechanism or the Blacklight assembly or even the light for the alarm readout, etc.

[radiodayz]

Following this thread. I have two of these. One is an actual Sony Digimatic, the other is branded Emerson, but was obviously made for them by Sony. On both the radio still works but not the clock mechanism. They are nice-sounding radios.

[ChrisW6ATV]

That is an interesting clock radio. I thought Sony always used the flip-digit type of digital clocks in their pre-LED/LCD days, but this one is indeed the digit-cylinder type of clock. I bought a Sony clock radio from the 1970s a while back and it has the flip-digit clock, as does my LV-1901 TV/VCR combo.

If the gears inside the clock motor have warped, they may be good candidates for 3D-printed replacements. You could look into that if you have not done so already. I wish you success.

[vortalexfan]

UPDATE: I'm going on about 3 months now since I've "rebuilt" the rotor I salvaged from the parts clock I bought from feebay and the clock is still running strong yet and it hasn't skipped a beat and is just as accurate as any of my other alarm clocks I have.

Now to give you my method I used to "rebuild" my rotor:

1.) I first disassembled the rotor assembly from the clock mechanism and removed the rotor from its plastic housing by removing the large step-up gear from the output shaft of the rotor and then popping the rotor out of its plastic housing.

2.) I then took an 1/8" drillbit and drilled a hole into the topside of the wider outer diameter of the rotor that way you avoid hitting the gears inside the rotor.

3.) I then dribbled some oil (20 wt non-detergent oil for electric motors for example) down into the rotor housing until it was just about to run out the hole that was drilled into the housing, and then I took a pair of pliers and gently rotated the output shaft on the rotor in the clockwise direction until I felt the gears inside the rotor free up inside and the rotor's output shaft would rotate freely without much effort from the pliers.

4.) I then finally sealed up the hole I drilled into the housing with some
high-temp silicone sealant and let it setup for 24 hours and then put the rotor back into its plastic housing reinstalled the step-up gear and reinstalled the rotor assembly back into the clock and plugged it in and sure enough the clock was running like new again (albeit a little on the noisy side but that's because its a Telechron based rotor and even the original Telechron rotors weren't completely silent when running correctly because its just the nature of the beast unfortunately.)

I hope this helps some people here resurrect their dead Sony Digimatics as well.