IC 6253B old cuckoo clock

Thread Starter

Kkmnew

Joined Nov 19, 2021
5
Hi Everyone,
My name is Kan and I am new to this forum.
There must be a genius here who know about this IC.,M6253B. It is used in an old cuckoo clock that I am trying to repair. Basically I would like to know the operation and pin diagram of this IC. If someone can kindly shed some light on this I would really appreciate it. Thanks in advance!
Regards
Kan
 
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sagor

Joined Mar 10, 2019
538
It might be a MSM6253 IC, a one time programmable microcontroller with A/D and other functions in an 18 pin narrow DIP or 20 pin wide DIP case. The MSM6253 was used in some older games like Sega. The "B" may be a clock speed rating or temperature rating.
If it is indeed a MSM6253, then it is a programmed CPU, and you will not likely find the code for the cuckoo clock. That is, it will not be replaceable unless you can find the original manufacturer and get the part from them.
Post a picture of the chip, it might help identify it here....
 

sagor

Joined Mar 10, 2019
538
The MSM6253 seems to be an 4 channel 8 bit A/D converter. Only PDF I can find seems to be in Japanese or Chinese. You can Google translate it...
 

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LesJones

Joined Jan 8, 2017
3,661
I could not find the datasheet for the M6253B but I found something suggesting it was a one time programmable micro controller.
I think it would be quicker to re design it around an easily available micro controller.

Les.
 

LesJones

Joined Jan 8, 2017
3,661
I think Bertus has found the answer. I think the silver coloured item near pin 5 is probably a 32.768 Khz crystal. A stepper motor driver fits in with an analogue clock. (When I saw the information suggesting it was a micro controller I assumed the display was digital which I thought to be strange on a cuckoo clock.) Answering Dodydave's question will be the bet way for us to be able to help you with the problem. Does the circuit synchronise a pendulum or are the hands driven by a stepper motor ?
Edit. Do you have an oscilloscope to look at the waveform on the pins of the IC ?

Les.
 
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The large coil in the picture above suggests this clock is based on a "kicker circuit", described by Big Clive in this video. The video shows a solar-powered flower with flapping leaves – I'll bet the operating principle is the same. (Clive has described this circuit in other videos for several types of moving objects, possibly including a clock).

If the clock is based on the same principle, the pendulum will contain a magnet that passes close to the coil. The circuit will pulse the coil as the pendulum swings by, giving it a kick to keep it moving and keeping it in sync. Since the oscillation of a pendulum is dependent on mass and the length of the lever arm, it will naturally stay close to the correct frequency and a little help from the circuit will keep it in time.

As I recall, Clive has looked at similar mechanisms with more discrete circuits. Spend a few minutes searching to find one.

Screenshot_20211119-102857_YouTube.jpg
 

Thread Starter

Kkmnew

Joined Nov 19, 2021
5
Hi Les,
I think I can get a hold of an oscilloscope. By tracing the pcb tracks. Pin#3 and 4 are connected a coils which makes the clock ticking. The motor that you see in the circuit is only driving the chimes function and it is working fine.
Kan
 
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