Help with crystal timed circuit

[utuvalet]

Hello all,



I am building a 1hz clock using a 32.768khz crystal, 4060IC, and a 4027IC.

I have built the circuit twice on a bread board driving it with a 9v battery and it works. I also have built the circuit 4 times on a circuit board with no luck. My last attempt is used the exact layout as in the schematic, which I got from hackers bench(crystal controlled 1hz based time clock).

I have no clue what is wrong. I am in desperate need of help and would greatly appreciate any information.



The component values are as follows:

LH IC=4060

RH IC=4027

R1=330KOHM

R2=6.8MOHM

R3=6.8MOHM

C1=33pf

C2=33pf

Y1=32.768KHZ

[pebe]

Hi,
Could you please reduce the size of your photo. Is is almost impossible to scan over it.

[utuvalet]

Sorry here is two more copies of the same image

[utuvalet]

Hope this helps

[pebe]

That's better - it's easier to read now.

Assuming there is no fault in your components or soldering, I think the most likely fault is failure of the Xtal oscillator.
The circuit in Hackers Bench is correct, but the layout they show is not. The data sheet for the 4060 shows R1 as being in series with the output pin, pin10. That prevents the low output impedance of the amp from damping the Xtal. In the layout, pin10 goes directly to the Xtal and R1 is in series with the clock input, pin11.

Changing over the connections to pins 10 & 11 of the 4060 should cure the problem.

[utuvalet]

Ok I switched pins 10 and 11 on my 4060 chip and it did not work. I am checking and double checking all of my connections/solder joints.

[pebe]

I would suspect the oscillator of the 4060. First, measure the voltage on pin 10, (preferably with an analogue meter). Half the time it should be high and the other half low, so it should read the average – ie. half the supply voltage. If you read it with a digital meter, the reading should ‘dither’ because a digital meter takes a series of instantaneous readings over a period of time and the meter is doing its best to display high and low alternately. But if it reads zero or the full supply voltage then the biasing of the oscillator is faulty. If so, check the PC tracks around the 2 x 6.8M resistors for shorts, and the value of the resistors.

Assuming the oscillator is OK, check the voltage on the RES pin – it should be zero volts. Then check Q14 output - it should be half rail. If not, the IC is faulty.

If all OK so far, the fault is around the 4027.