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Old 02-16-2017, 02:21 PM
Captainclock Captainclock is offline
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Sankyo Model SCR-700 AM/FM "Digital" Clock Radio issues

Hello everyone a few months ago I went to the local Habitat for Humanity Restore and browsed around for a bit and found this interesting clock radio that was an early "digital" alarm clock radio digital in quotes because its technically analog yet because its one of those "flip-dial" style clocks that were touted as being "digital", but what's rather unique about this clock is that instead of flaps that "flip" revealing the current time, this one has rotating drums painted with different designs that when they pass over the "screen" they reveal the current time and the funny part is that the clock was made in Taiwan for Sankyo which is a Japanese company but it uses an Intermatic timer motor which Intermatic is an American Company (or at least it was at the time this clock radio was made, and I think it still is).

But anyways when I first got this unit the clock part wasn't working (as is the case most of the time with these old "digital" clocks).
But I took the unit apart and saw the that the motor driving the clock mechanism was the same type of motor that's found in your old Intermatic wall timers that are used to turn lamps on and off, which I had just so happened to have a couple of those hanging around for parts because they weren't working right.
Anyways it turned out that the main drive gear that went from the motor shaft to the step-down gears for driving the gear that drives the clock movement was stripped out so I took the main drive gear off of one of my old Intermatic timers and stuck it into the motor on this clock radio and sure enough the clock started working again.

Then there was the issue of the burned out incandecent backlight for the clock which was basically a 12V Wedge Base light bulb like what your cars and some stereo receivers use for their backlights that had wires pigtailed to it and was mounted into a wedge base socket holder, so I replaced that with a 12V miniature incandecent bulb like what is used to light the FM Stereo light on some of your old Stereo Receivers and now it lights up again.
Although I'm planning on wiring in a Wedge-Base light bulb socket to the thing so that I can put a wedge-base bulb in again, but instead of it having to be soldered in place like it was originally it can be replaced whenever its burned out.

Anyways the problem I'm having with this unit now is that the alarm doesn't work on this unit anymore, it has an electronic "buzzer" that when its set to sound the buzzer for the alarm it would sound off an electronic reproduction of the classic "buzzer" sound you would hear on the old analog electric alarm clocks.
At first it worked fine but then gradually over time the buzzer got scratchy and intermittent sounding and now it doesn't even go off at all period, and also when you have the alarm set to go off in radio mode the radio doesn't come on to the alarm trigger at all its just silent, all you hear is the alarm trigger being tripped but the radio doesn't come on.

Any ideas as to what could be causing the alarm on this clock radio to not work anymore?

Any information and or help would be greatly appreciated.

Thanks,

Levi

P.S. Apparently this is a fairly scarce alarm clock radio model because I went to look up this clock radio model online and it returned zero results! Not even GIS! Also a picture of the clock in question is posted below.

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Last edited by Celt; 02-17-2017 at 07:18 AM.
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Old 02-17-2017, 12:41 AM
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jr_tech jr_tech is offline
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Does the radio work if you turn it on manually? Might be just dirty contacts on the alarm switch causing the "buzzer" and the radio to not work.

jr
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Old 02-17-2017, 01:53 AM
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MadMan MadMan is offline
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Yeah I'd second dirty contacts. Anything else would probably be intermittent, rather than fade to nothing. But still could be a broken solder joint somewhere.

Also, cool clock! I have an orange Sankyo digital clock, no radio on that one, just a buzzer. And the digits aren't as cool looking, but they are the drum type.
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Old 02-17-2017, 10:51 AM
Captainclock Captainclock is offline
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Thanks, and yes the radio comes on manually and the sleep feature works too, its just the alarm part don't work anymore, but I'll be sure to check into the maybe spraying some contact cleaner into the switch for the alarm function and see if that doesn't fix it.
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Old 02-17-2017, 02:46 PM
Captainclock Captainclock is offline
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Well I got the buzzer part working again, but the radio part doesn't work with the alarm feature (when the alarm goes off the radio comes on instead of the buzzer) and I did clean the contacts on the switches as best as I could (the switches are sealed except for a small hole on the top of the switch which is barely accessible). So what else could be causing the radio portion of the alarm function to be non-functioning, but the buzzer part to be functional?
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Old 02-17-2017, 05:44 PM
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jr_tech jr_tech is offline
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Just a WAG, but perhaps the top (mode?) switches could use a good cleaning, as well.

jr
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Old 02-17-2017, 07:37 PM
Captainclock Captainclock is offline
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Quote:
Originally Posted by jr_tech View Post
Just a WAG, but perhaps the top (mode?) switches could use a good cleaning, as well.

jr
Those mode switches are the switches I cleaned and it only brought back the buzzer's functionality for the alarm but not the radio's functionality for the alarm function, also what other swithches did you think we were talking about besides those top switches? Because those top switches are the only switches on this radio for selecting the functions of this clock radio. The far right switch is for selecting the radio Band, the middle right switch is for selecting the alarm mode (whether the alarm comes on with the buzzer or the radio), the middle left switch is the Auto/Manual selection switch which either switches the radio on manually or automatically via the alarm, and the far left switch is the power swich which is the master power switch which has to be on in order for the sleep timer and the alarm to work along with the manual/automatic switch being set to automatic. This radio functions very much like the old flip-dial Sony Dream Machine alarm clocks. Hope this helps.

Last edited by Captainclock; 02-17-2017 at 07:45 PM.
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Old 02-17-2017, 10:39 PM
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jr_tech jr_tech is offline
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There must be a switch inside the clock mechanism that is activated at the set time.

jr
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Old 02-18-2017, 04:45 PM
Captainclock Captainclock is offline
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Quote:
Originally Posted by jr_tech View Post
There must be a switch inside the clock mechanism that is activated at the set time.

jr
Strage part is that since I got the buzzer part going again, the radio part of the radio function of the alarm will activate but only if the manual/auto button is switched to manual and then back to Auto again then the radio works with the alarm, but then when you switch it back to buzzer mode and then back to radio again the radio quits working again with the alarm until you hit the manual/auto switch again so there's definitely something funky going on with the circuitry associated with the mode/power switches on the top.
And yes I know theres a switch inside that allows the clock mechanism to activate the alarm at the preset time, its a small momentary SPST switch that is activated by a small metal lever that kicks up against the switch at the set time and then triggers the alarm.
But I don't think that switch is what's causing my issues, its something to do with the mode/power switch circuitry on the top of the unit because like I said the buzzer works like its supposed to, but the radio will only work with the alarm if the auto/manual switch is switched to manual and then back to auto, but its only temporary because as soon as you switch the alarm mode switch back to buzzer and then back to radio the radio is dead silent again, but like I said the buzzer works fine regardless.
What's interesting is that the condition with the radio not working with the alarm unless the auto/manual switch is triggered to manual and then back to auto in radio mode for the alarm is what this unit did when I first got it before the alarm started acting up, so I don't know what to say about this issue.
I know this unit is supposed to be able to have the radio come on with the alarm because otherwise it wouldn't have an alarm mode switch with the option for radio or buzzer built in, so obviously its not that the alarm doesn't have the option for the radio to come on with the alarm because it does, its just that something in the circuitry isn't allowing the radio to trigger with the alarm when the alarm is set to radio mode.

Last edited by Captainclock; 02-18-2017 at 04:56 PM.
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